YourPhone.Shell

The Dependency property backing the ViewModel property

Gets or sets the viewmodel the chrome binds to.

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

An empty window that can be used on its own or navigated to within a Frame.

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

This protocol parser handles the app protocol, as well as a null protocol if we have a device.

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

The Dependency property backing the ViewModel property

Gets or sets the viewmodel the chrome binds to.

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

Small: 2 Default: 8 Medium: 16 Large: 24 ExtraLarge:32

Elements Spacing Height VericalContentAlignment customStyle customHeight minHeight minItemHeight itemSpacing cornerRadius title tooltip string

Defines the source generated JSON serialization contract metadata for a given type.

The default associated with a default instance.

The source-generated options associated with this context.

This method is used to remove the broken Start registry key if it exists. This is caused by a bug in PL where we accidentally create the Start registry key and because of that the key gets the wrong ACL.

A boolean to indicate if we deleted the key.

The Dependency property backing the ViewModel property

Gets or sets the viewmodel the chrome binds to.

InitializeComponent()

UnloadObject(DependencyObject)

Connect()

DisconnectUnloadedObject(int connectionId)

GetBindingConnector(int connectionId, object target)

Clears the search box text

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

The Dependency property backing the ViewModel property

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

The Dependency property backing the ViewModel property

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

The Dependency property backing the ViewModel property

InitializeComponent()

Connect()

GetBindingConnector(int connectionId, object target)

Simplified skeleton view model for the AI search functionality

Initializes a new instance of the class

Gets or sets the search results returned by the AI

Gets or sets a value indicating whether a search is in progress

Execute a search query against the AI service

The search query text A token to monitor for cancellation requests A task representing the asynchronous operation

Factory class for creating AI search related views

Initializes a new instance of the class.

The view model to use with created views

Creates a new instance of the AISearchBox control

The device data, used for device-specific customizations An AISearchBox control instance

Handle the Activate call. This function is called when widgets host starts listening to the widget updates. It generally happens when the widget becomes visible and the updates will be promptly displayed to the user. It's recommended to start sending updates from this moment until Deactivate function was called.

Handle the CreateWidget call. During this function call you should store the WidgetId value so you can use it to update corresponding widget. It is our way of notifying you that the user has pinned your widget and you should start pushing updates.

Handle the Deactivate call. This function is called when widgets host stops listening to the widget updates. It generally happens when the widget is not visible to the user anymore and any further updates won't be displayed until the widget is visible again. It's recommended to stop sending updates until Activate function was called.

Handle the DeleteWidget call. This is notifying you that you don't need to provide new content for the given WidgetId since the user has unpinned the widget or it was deleted by the Host for any other reason.

Handle the OnActionInvoked call. This function call is fired when the user's interaction with the widget resulted in an execution of one of the defined actions that you've indicated in the template of the Widget. For example: clicking a button or submitting input.

Handle the WidgetContextChanged call. This function is called when the context a widget has changed. Currently it only signals that the user has changed the size of the widget. There are 2 ways to respond to this event: 1) Call UpdateWidget() with the new data/template to fit the new requested size. 2) If previously sent data/template accounts for various sizes based on $host.widgetSize - you can use this event solely for telemtry.

Defines the source generated JSON serialization contract metadata for a given type.

The default associated with a default instance.

The source-generated options associated with this context.

Defines the source generated JSON serialization contract metadata for a given type.

The default associated with a default instance.

The source-generated options associated with this context.

Main class for providing metadata for the app or library

GetXamlType(Type)

GetXamlType(String)

GetXmlnsDefinitions()

The **HRESULT** data type is the same as the [SCODE](scode.md) data type. An **HRESULT** value consists of the following fields: - A 1-bit code indicating severity, where zero represents success and 1 represents failure. - A 4-bit reserved value. - An 11-bit code indicating responsibility for the error or warning, also known as a facility code. - A 16-bit code describing the error or warning. Most MAPI interface methods and functions return **HRESULT** values to provide detailed cause formation. **HRESULT** values are also used widely in OLE interface methods. OLE provides several macros for converting between **HRESULT** values and **SCODE** values, another common data type for error handling. > [!NOTE] > In 64-bit MAPI, **HRESULT** is still a 32-bit value. For information about the OLE use of **HRESULT** values, see the *OLE Programmer's Reference*. For more information about the use of these values in MAPI, see [Error Handling](error-handling-in-mapi.md) and any of the following interface methods: [IABLogon::GetLastError](iablogon-getlasterror.md) [IMAPISupport::GetLastError](imapisupport-getlasterror.md) [IMAPIControl::GetLastError](imapicontrol-getlasterror.md) [IMAPITable::GetLastError](imapitable-getlasterror.md) [IMAPIProp::GetLastError](imapiprop-getlasterror.md) [IMAPIViewAdviseSink::OnPrint](imapiviewadvisesink-onprint.md) Read more on docs.microsoft.com. A pointer to the IErrorInfo interface that provides more information about the error. You can specify to use the current IErrorInfo interface, or new IntPtr(-1) to ignore the current IErrorInfo interface and construct the exception just from the error code. , if it does not reflect an error.

A pointer to a null-terminated, constant character string.

A pointer to the first character in the string. The content should be considered readonly, as it was typed as constant in the SDK.

Gets the number of characters up to the first null character (exclusive).

Returns a with a copy of this character array, up to the first null character (exclusive).

A , or if is .

Returns a span of the characters in this string, up to the first null character (exclusive).

The RECT structure defines a rectangle by the coordinates of its upper-left and lower-right corners.

The RECT structure is identical to the RECTL structure.

Specifies the x-coordinate of the upper-left corner of the rectangle.

Specifies the y-coordinate of the upper-left corner of the rectangle.

Specifies the x-coordinate of the lower-right corner of the rectangle.

Specifies the y-coordinate of the lower-right corner of the rectangle.

The SIZE structure defines the width and height of a rectangle.

The rectangle dimensions stored in this structure can correspond to viewport extents, window extents, text extents, bitmap dimensions, or the aspect-ratio filter for some extended functions.

Specifies the rectangle's width. The units depend on which function uses this structure.

Specifies the rectangle's height. The units depend on which function uses this structure.

The length of the inline array.

Gets a ref to an individual element of the inline array. ⚠ Important ⚠: When this struct is on the stack, do not let the returned reference outlive the stack frame that defines it.

Gets this inline array as a span.

⚠ Important ⚠: When this struct is on the stack, do not let the returned span outlive the stack frame that defines it.

Gets this inline array as a span.

⚠ Important ⚠: When this struct is on the stack, do not let the returned span outlive the stack frame that defines it.

Copies the fixed array to a new string up to the specified length regardless of whether there are null terminating characters.

Thrown when is less than 0 or greater than .

Copies the fixed array to a new string, stopping before the first null terminator character or at the end of the fixed array (whichever is shorter).

The length of the inline array.

Gets a ref to an individual element of the inline array. ⚠ Important ⚠: When this struct is on the stack, do not let the returned reference outlive the stack frame that defines it.

Gets this inline array as a span.

⚠ Important ⚠: When this struct is on the stack, do not let the returned span outlive the stack frame that defines it.

Gets this inline array as a span.

⚠ Important ⚠: When this struct is on the stack, do not let the returned span outlive the stack frame that defines it.

Copies the fixed array to a new string up to the specified length regardless of whether there are null terminating characters.

Thrown when is less than 0 or greater than .

Copies the fixed array to a new string, stopping before the first null terminator character or at the end of the fixed array (whichever is shorter).

The length of the inline array.

Gets a ref to an individual element of the inline array. ⚠ Important ⚠: When this struct is on the stack, do not let the returned reference outlive the stack frame that defines it.

Gets this inline array as a span.

⚠ Important ⚠: When this struct is on the stack, do not let the returned span outlive the stack frame that defines it.

Gets this inline array as a span.

⚠ Important ⚠: When this struct is on the stack, do not let the returned span outlive the stack frame that defines it.

Copies the fixed array to a new string up to the specified length regardless of whether there are null terminating characters.

Thrown when is less than 0 or greater than .

Copies the fixed array to a new string, stopping before the first null terminator character or at the end of the fixed array (whichever is shorter).

Contains data to be passed to another application by the WM_COPYDATA message.

Learn more about this API from docs.microsoft.com.

Type: ULONG_PTR The type of the data to be passed to the receiving application. The receiving application defines the valid types. Read more on docs.microsoft.com.

Type: DWORD The size, in bytes, of the data pointed to by the lpData member. Read more on docs.microsoft.com.

Type: PVOID The data to be passed to the receiving application. This member can be NULL. Read more on docs.microsoft.com.

Contains information about a menu item. (MENUITEMINFOW)

The MENUITEMINFO structure is used with the GetMenuItemInfo, InsertMenuItem, and SetMenuItemInfo functions. The menu can display items using text, bitmaps, or both. > [!NOTE] > The winuser.h header defines MENUITEMINFO as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com.

Type: UINT The size of the structure, in bytes. The caller must set this member to sizeof(MENUITEMINFO). Read more on docs.microsoft.com.

Type: UINT

Type: UINT The menu item state. This member can be one or more of these values. Set fMask to MIIM_STATE to use fState. This doc was truncated. Read more on docs.microsoft.com.

Type: UINT An application-defined value that identifies the menu item. Set fMask to MIIM_ID to use wID. Read more on docs.microsoft.com.

Type: HMENU A handle to the drop-down menu or submenu associated with the menu item. If the menu item is not an item that opens a drop-down menu or submenu, this member is NULL. Set fMask to MIIM_SUBMENU to use hSubMenu. Read more on docs.microsoft.com.

Type: HBITMAP A handle to the bitmap to display next to the item if it is selected. If this member is NULL, a default bitmap is used. If the MFT_RADIOCHECK type value is specified, the default bitmap is a bullet. Otherwise, it is a check mark. Set fMask to MIIM_CHECKMARKS to use hbmpChecked. Read more on docs.microsoft.com.

Type: HBITMAP A handle to the bitmap to display next to the item if it is not selected. If this member is NULL, no bitmap is used. Set fMask to MIIM_CHECKMARKS to use hbmpUnchecked. Read more on docs.microsoft.com.

Type: ULONG_PTR An application-defined value associated with the menu item. Set fMask to MIIM_DATA to use dwItemData. Read more on docs.microsoft.com.

Type: LPTSTR The contents of the menu item. The meaning of this member depends on the value of fType and is used only if the MIIM_TYPE flag is set in the fMask member. To retrieve a menu item of type MFT_STRING, first find the size of the string by setting the dwTypeData member of MENUITEMINFO to NULL and then calling GetMenuItemInfo. The value of cch+1 is the size needed. Then allocate a buffer of this size, place the pointer to the buffer in dwTypeData, increment cch, and call GetMenuItemInfo once again to fill the buffer with the string. If the retrieved menu item is of some other type, then GetMenuItemInfo sets the dwTypeData member to a value whose type is specified by the fType member. When using with the SetMenuItemInfo function, this member should contain a value whose type is specified by the fType member. dwTypeData is used only if the MIIM_STRING flag is set in the fMask member Read more on docs.microsoft.com.

Type: UINT The length of the menu item text, in characters, when information is received about a menu item of the MFT_STRING type. However, cch is used only if the MIIM_TYPE flag is set in the fMask member and is zero otherwise. Also, cch is ignored when the content of a menu item is set by calling SetMenuItemInfo. Note that, before calling GetMenuItemInfo, the application must set cch to the length of the buffer pointed to by the dwTypeData member. If the retrieved menu item is of type MFT_STRING (as indicated by the fType member), then GetMenuItemInfo changes cch to the length of the menu item text. If the retrieved menu item is of some other type, GetMenuItemInfo sets the cch field to zero. The cch member is used when the MIIM_STRING flag is set in the fMask member. Read more on docs.microsoft.com.

Type: HBITMAP A handle to the bitmap to be displayed, or it can be one of the values in the following table. It is used when the MIIM_BITMAP flag is set in the fMask member. This doc was truncated. Read more on docs.microsoft.com.

Contains extended parameters for the TrackPopupMenuEx function.

Learn more about this API from docs.microsoft.com.

Type: UINT The size of structure, in bytes. Read more on docs.microsoft.com.

Type: RECT The rectangle to be excluded when positioning the window, in screen coordinates. Read more on docs.microsoft.com.

Contains window class information. (Unicode)

> [!NOTE] > The winuser.h header defines WNDCLASSEX as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com.

Type: UINT The size, in bytes, of this structure. Set this member to sizeof(WNDCLASSEX). Be sure to set this member before calling the GetClassInfoEx function. Read more on docs.microsoft.com.

Type: UINT The class style(s). This member can be any combination of the Class Styles. Read more on docs.microsoft.com.

Type: WNDPROC A pointer to the window procedure. You must use the CallWindowProc function to call the window procedure. For more information, see WindowProc. Read more on docs.microsoft.com.

Type: int The number of extra bytes to allocate following the window-class structure. The system initializes the bytes to zero. Read more on docs.microsoft.com.

Type: int The number of extra bytes to allocate following the window instance. The system initializes the bytes to zero. If an application uses WNDCLASSEX to register a dialog box created by using the CLASS directive in the resource file, it must set this member to DLGWINDOWEXTRA. Read more on docs.microsoft.com.

Type: HINSTANCE A handle to the instance that contains the window procedure for the class. Read more on docs.microsoft.com.

Type: HICON A handle to the class icon. This member must be a handle to an icon resource. If this member is NULL, the system provides a default icon. Read more on docs.microsoft.com.

Type: HCURSOR A handle to the class cursor. This member must be a handle to a cursor resource. If this member is NULL, an application must explicitly set the cursor shape whenever the mouse moves into the application's window. Read more on docs.microsoft.com.

Type: HBRUSH A handle to the class background brush. This member can be a handle to the brush to be used for painting the background, or it can be a color value. A color value must be one of the following standard system colors (the value 1 must be added to the chosen color). If a color value is given, you must convert it to one of the following HBRUSH types: This doc was truncated. Read more on docs.microsoft.com.

Type: LPCTSTR Pointer to a null-terminated character string that specifies the resource name of the class menu, as the name appears in the resource file. If you use an integer to identify the menu, use the MAKEINTRESOURCE macro. If this member is NULL, windows belonging to this class have no default menu. Read more on docs.microsoft.com.

Type: LPCTSTR A pointer to a null-terminated string or is an atom. If this parameter is an atom, it must be a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpszClassName; the high-order word must be zero. If lpszClassName is a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, or any of the predefined control-class names. The maximum length for lpszClassName is 256. If lpszClassName is greater than the maximum length, the RegisterClassEx function will fail. Read more on docs.microsoft.com.

Type: HICON A handle to a small icon that is associated with the window class. If this member is NULL, the system searches the icon resource specified by the hIcon member for an icon of the appropriate size to use as the small icon. Read more on docs.microsoft.com.

Identifies the dots per inch (dpi) setting for a monitor.

All of these settings are affected by the PROCESS_DPI_AWARENESS of your application

The effective DPI. This value should be used when determining the correct scale factor for scaling UI elements. This incorporates the scale factor set by the user for this specific display.

The angular DPI. This DPI ensures rendering at a compliant angular resolution on the screen. This does not include the scale factor set by the user for this specific display.

The raw DPI. This value is the linear DPI of the screen as measured on the screen itself. Use this value when you want to read the pixel density and not the recommended scaling setting. This does not include the scale factor set by the user for this specific display and is not guaranteed to be a supported DPI value.

The default DPI setting for a monitor is MDT_EFFECTIVE_DPI.

Contains information that the system needs to display notifications in the notification area. Used by Shell_NotifyIcon. (Unicode)

See Notifications in the Windows User Experience Interaction Guidelines for more information on notification UI and content best practices. If you set the NIF_INFO flag in the uFlags member, the balloon-style notification is used. For more discussion of these notifications, see Balloon tooltips. No more than one balloon notification at a time can be displayed for the taskbar. If an application attempts to display a notification when one is already being displayed, the new notification is queued and displayed when the older notification goes away. In versions of Windows before Windows Vista, the new notification would not appear until the existing notification has been visible for at least the system minimum timeout length, regardless of the original notification's uTimeout value. If the user does not appear to be using the computer, the system does not count this time toward the timeout. Several members of this structure are only supported for Windows 2000 and later. To enable these members, include one of the following lines in your header: This doc was truncated. Read more on docs.microsoft.com.

Type: DWORD The size of this structure, in bytes. Read more on docs.microsoft.com.

Type: HWND A handle to the window that receives notifications associated with an icon in the notification area. Read more on docs.microsoft.com.

Type: UINT The application-defined identifier of the taskbar icon. The Shell uses either (hWnd plus uID) or guidItem to identify which icon to operate on when Shell_NotifyIcon is invoked. You can have multiple icons associated with a single hWnd by assigning each a different uID. If guidItem is specified, uID is ignored. Read more on docs.microsoft.com.

Type: UINT

Type: UINT An application-defined message identifier. The system uses this identifier to send notification messages to the window identified in hWnd. These notification messages are sent when a mouse event or hover occurs in the bounding rectangle of the icon, when the icon is selected or activated with the keyboard, or when those actions occur in the balloon notification. When the uVersion member is either 0 or NOTIFYICON_VERSION, the wParam parameter of the message contains the identifier of the taskbar icon in which the event occurred. This identifier can be 32 bits in length. The lParam parameter holds the mouse or keyboard message associated with the event. For example, when the pointer moves over a taskbar icon, lParam is set to WM_MOUSEMOVE. When the uVersion member is NOTIFYICON_VERSION_4, applications continue to receive notification events in the form of application-defined messages through the uCallbackMessage member, but the interpretation of the lParam and wParam parameters of that message is changed as follows: This doc was truncated. Read more on docs.microsoft.com.

Type: HICON A handle to the icon to be added, modified, or deleted. Windows XP and later support icons of up to 32 BPP. If only a 16x16 pixel icon is provided, it is scaled to a larger size in a system set to a high dpi value. This can lead to an unattractive result. It is recommended that you provide both a 16x16 pixel icon and a 32x32 icon in your resource file. Use LoadIconMetric to ensure that the correct icon is loaded and scaled appropriately. See Remarks for a code example. Read more on docs.microsoft.com.

Type: TCHAR[64] A null-terminated string that specifies the text for a standard tooltip. It can have a maximum of 64 characters, including the terminating null character. For Windows 2000 and later, szTip can have a maximum of 128 characters, including the terminating null character. Read more on docs.microsoft.com.

Type: DWORD

Type: DWORD Windows 2000 and later. A value that specifies which bits of the dwState member are retrieved or modified. The possible values are the same as those for dwState. For example, setting this member to NIS_HIDDEN causes only the item's hidden state to be modified while the icon sharing bit is ignored regardless of its value. Read more on docs.microsoft.com.

Type: TCHAR[256] Windows 2000 and later. A null-terminated string that specifies the text to display in a balloon notification. It can have a maximum of 256 characters, including the terminating null character, but should be restricted to 200 characters in English to accommodate localization. To remove the balloon notification from the UI, either delete the icon (with NIM_DELETE) or set the NIF_INFO flag in uFlags and set szInfo to an empty string. Read more on docs.microsoft.com.

Type: TCHAR[64] Windows 2000 and later. A null-terminated string that specifies a title for a balloon notification. This title appears in a larger font immediately above the text. It can have a maximum of 64 characters, including the terminating null character, but should be restricted to 48 characters in English to accommodate localization. Read more on docs.microsoft.com.

Type: DWORD Windows 2000 and later. Flags that can be set to modify the behavior and appearance of a balloon notification. The icon is placed to the left of the title. If the szInfoTitle member is zero-length, the icon is not shown. Read more on docs.microsoft.com.

Type: GUID Windows XP and later. This doc was truncated. Read more on docs.microsoft.com.

Type: HICON Windows Vista and later. The handle of a customized notification icon provided by the application that should be used independently of the notification area icon. If this member is non-NULL and the NIIF_USER flag is set in the dwInfoFlags member, this icon is used as the notification icon. If this member is NULL, the legacy behavior is carried out. Read more on docs.microsoft.com.

Contains information used by Shell_NotifyIconGetRect to identify the icon for which to retrieve the bounding rectangle.

The icon can be identified to Shell_NotifyIconGetRect through this structure in two ways: This doc was truncated. Read more on docs.microsoft.com.

Type: DWORD The size of this structure, in bytes. Read more on docs.microsoft.com.

Type: HWND A handle to the parent window used by the notification's callback function. For more information, see the hWnd member of the NOTIFYICONDATA structure. Read more on docs.microsoft.com.

Type: UINT The application-defined identifier of the notification icon. Multiple icons can be associated with a single hWnd, each with their own uID. Read more on docs.microsoft.com.

Type: GUID A registered GUID that identifies the icon. Use GUID_NULL if the icon is not identified by a GUID. Read more on docs.microsoft.com.

Represents a Win32 handle that can be closed with .

Contains extern methods from "api-ms-win-shcore-scaling-l1-1-1.dll". Contains extern methods from "GDI32.dll". Contains extern methods from "KERNEL32.dll". Contains extern methods from "SHELL32.dll". Contains extern methods from "USER32.dll".

Queries the dots per inch (dpi) of a display.

Handle of the monitor being queried. The type of DPI being queried. Possible values are from the MONITOR_DPI_TYPE enumeration. The value of the DPI along the X axis. This value always refers to the horizontal edge, even when the screen is rotated. The value of the DPI along the Y axis. This value always refers to the vertical edge, even when the screen is rotated. This function returns one of the following values. This doc was truncated. This API is not DPI aware and should not be used if the calling thread is per-monitor DPI aware. For the DPI-aware version of this API, see GetDpiForWindow. When you call GetDpiForMonitor, you will receive different DPI values depending on the DPI awareness of the calling application. DPI awareness is an application-level property usually defined in the application manifest. For more information about DPI awareness values, see PROCESS_DPI_AWARENESS. The following table indicates how the results will differ based on the PROCESS_DPI_AWARENESS value of your application. This doc was truncated. Read more on docs.microsoft.com.

Sent when a window is being destroyed. It is sent to the window procedure of the window being destroyed after the window is removed from the screen.

Type: **LRESULT** If an application processes this message, it should return zero. If the window being destroyed is part of the clipboard viewer chain (set by calling the [**SetClipboardViewer**](/windows/win32/api/winuser/nf-winuser-setclipboardviewer) function), the window must remove itself from the chain by processing the [**ChangeClipboardChain**](/windows/win32/api/winuser/nf-winuser-changeclipboardchain) function before returning from the **WM\_DESTROY** message.

Used to define private messages for use by private window classes, usually of the form WM\_USER+x, where x is an integer value.

The following are the ranges of message numbers. | Range | Meaning | |--------------------------------------------------------------|----------------------------------------------------------------| | 0 through **WM\_USER** –1
| Messages reserved for use by the system.
| | **WM\_USER** through 0x7FFF
| Integer messages for use by private window classes.
| | [**WM\_APP**](wm-app.md) (0x8000) through 0xBFFF
| Messages available for use by applications.
| | 0xC000 through 0xFFFF
| String messages for use by applications.
| | Greater than 0xFFFF
| Reserved by the system.
| Message numbers in the first range (0 through **WM\_USER** –1) are defined by the system. Values in this range that are not explicitly defined are reserved by the system. Message numbers in the second range (**WM\_USER** through 0x7FFF) can be defined and used by an application to send messages within a private window class. These values cannot be used to define messages that are meaningful throughout an application because some predefined window classes already define values in this range. For example, predefined control classes such as **BUTTON**, **EDIT**, **LISTBOX**, and **COMBOBOX** may use these values. Messages in this range should not be sent to other applications unless the applications have been designed to exchange messages and to attach the same meaning to the message numbers. Message numbers in the third range (0x8000 through 0xBFFF) are available for applications to use as private messages. Messages in this range do not conflict with system messages. Message numbers in the fourth range (0xC000 through 0xFFFF) are defined at run time when an application calls the [**RegisterWindowMessage**](/windows/win32/api/winuser/nf-winuser-registerwindowmessagea) function to retrieve a message number for a string. All applications that register the same string can use the associated message number for exchanging messages. The actual message number, however, is not a constant and cannot be assumed to be the same between different sessions. Message numbers in the fifth range (greater than 0xFFFF) are reserved by the system. Read more on docs.microsoft.com.

Posted when the user releases the left mouse button while the cursor is in the client area of a window.

If an application processes this message, it should return zero. Use the following code to obtain the horizontal and vertical position: This doc was truncated. Read more on docs.microsoft.com.

Posted when the user releases the right mouse button while the cursor is in the client area of a window.

If an application processes this message, it should return zero. Use the following code to obtain the horizontal and vertical position: This doc was truncated. Read more on docs.microsoft.com.

Posted when the user double-clicks the left mouse button while the cursor is in the client area of a window.

If an application processes this message, it should return zero. Use the following code to obtain the horizontal and vertical position: This doc was truncated. Read more on docs.microsoft.com.

A window receives this message when the user chooses a command from the Window menu (formerly known as the system or control menu) or when the user chooses the maximize button, minimize button, restore button, or close button.

An application should return zero if it processes this message. To obtain the position coordinates in screen coordinates, use the following code: This doc was truncated. Read more on docs.microsoft.com.

An application sends the WM\_COPYDATA message to pass data to another application.

If the receiving application processes this message, it should return **TRUE**; otherwise, it should return **FALSE**. The data being passed must not contain pointers or other references to objects not accessible to the application receiving the data. While this message is being sent, the referenced data must not be changed by another thread of the sending process. The receiving application should consider the data read-only. The *lParam* parameter is valid only during the processing of the message. The receiving application should not free the memory referenced by *lParam*. If the receiving application must access the data after [**SendMessage**](/windows/desktop/api/winuser/nf-winuser-sendmessage) returns, it must copy the data into a local buffer. Read more on docs.microsoft.com.

The DeleteObject function deletes a logical pen, brush, font, bitmap, region, or palette, freeing all system resources associated with the object. After the object is deleted, the specified handle is no longer valid.

A handle to a logical pen, brush, font, bitmap, region, or palette. If the function succeeds, the return value is nonzero. If the specified handle is not valid or is currently selected into a DC, the return value is zero. Do not delete a drawing object (pen or brush) while it is still selected into a DC. When a pattern brush is deleted, the bitmap associated with the brush is not deleted. The bitmap must be deleted independently. Read more on docs.microsoft.com.

Closes an open object handle.

A valid handle to an open object. If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. If the application is running under a debugger, the function will throw an exception if it receives either a handle value that is not valid or a pseudo-handle value. This can happen if you close a handle twice, or if you call CloseHandle on a handle returned by the FindFirstFile function instead of calling the FindClose function. The CloseHandle function closes handles to the following objects: This doc was truncated. Read more on docs.microsoft.com.

Frees the loaded dynamic-link library (DLL) module and, if necessary, decrements its reference count.

A handle to the loaded library module. The LoadLibrary, LoadLibraryEx, GetModuleHandle, or GetModuleHandleEx function returns this handle. Read more on docs.microsoft.com. If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call the GetLastError function. The system maintains a per-process reference count for each loaded module. A module that was loaded at process initialization due to load-time dynamic linking has a reference count of one. The reference count for a module is incremented each time the module is loaded by a call to LoadLibrary. The reference count is also incremented by a call to LoadLibraryEx unless the module is being loaded for the first time and is being loaded as a data or image file. The reference count is decremented each time the FreeLibrary or FreeLibraryAndExitThread function is called for the module. When a module's reference count reaches zero or the process terminates, the system unloads the module from the address space of the process. Before unloading a library module, the system enables the module to detach from the process by calling the module's DllMain function, if it has one, with the DLL_PROCESS_DETACH value. Doing so gives the library module an opportunity to clean up resources allocated on behalf of the current process. After the entry-point function returns, the library module is removed from the address space of the current process. It is not safe to call FreeLibrary from DllMain. For more information, see the Remarks section in DllMain. Calling FreeLibrary does not affect other processes that are using the same module. Use caution when calling FreeLibrary with a handle returned by GetModuleHandle. The GetModuleHandle function does not increment a module's reference count, so passing this handle to FreeLibrary can cause a module to be unloaded prematurely. A thread that must unload the DLL in which it is executing and then terminate itself should call FreeLibraryAndExitThread instead of calling FreeLibrary and ExitThread separately. Otherwise, a race condition can occur. For details, see the Remarks section of FreeLibraryAndExitThread. Read more on docs.microsoft.com.

Retrieves a module handle for the specified module. The module must have been loaded by the calling process. (Unicode)

The name of the loaded module (either a .dll or .exe file). If the file name extension is omitted, the default library extension .dll is appended. The file name string can include a trailing point character (.) to indicate that the module name has no extension. The string does not have to specify a path. When specifying a path, be sure to use backslashes (\\), not forward slashes (/). The name is compared (case independently) to the names of modules currently mapped into the address space of the calling process. If this parameter is NULL, GetModuleHandle returns a handle to the file used to create the calling process (.exe file). The GetModuleHandle function does not retrieve handles for modules that were loaded using the LOAD_LIBRARY_AS_DATAFILE flag. For more information, see LoadLibraryEx. Read more on docs.microsoft.com. If the function succeeds, the return value is a handle to the specified module. If the function fails, the return value is NULL. To get extended error information, call GetLastError. The returned handle is not global or inheritable. It cannot be duplicated or used by another process. If lpModuleName does not include a path and there is more than one loaded module with the same base name and extension, you cannot predict which module handle will be returned. To work around this problem, you could specify a path, use side-by-side assemblies, or use GetModuleHandleEx to specify a memory location rather than a DLL name. The GetModuleHandle function returns a handle to a mapped module without incrementing its reference count. However, if this handle is passed to the FreeLibrary function, the reference count of the mapped module will be decremented. Therefore, do not pass a handle returned by GetModuleHandle to the FreeLibrary function. Doing so can cause a DLL module to be unmapped prematurely. This function must be used carefully in a multithreaded application. There is no guarantee that the module handle remains valid between the time this function returns the handle and the time it is used. For example, suppose that a thread retrieves a module handle, but before it uses the handle, a second thread frees the module. If the system loads another module, it could reuse the module handle that was recently freed. Therefore, the first thread would have a handle to a different module than the one intended. Read more on docs.microsoft.com.

Gets the screen coordinates of the bounding rectangle of a notification icon.

Type: const NOTIFYICONIDENTIFIER* Pointer to a NOTIFYICONIDENTIFIER structure that identifies the icon. Read more on docs.microsoft.com. Type: RECT* Pointer to a RECT structure that, when this function returns successfully, receives the coordinates of the icon. Read more on docs.microsoft.com. Type: HRESULT If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code. Learn more about this API from docs.microsoft.com.

Sends a message to the taskbar's status area. (Unicode)

Type: DWORD Type: PNOTIFYICONDATA A pointer to a NOTIFYICONDATA structure. The content of the structure depends on the value of dwMessage. It can define an icon to add to the notification area, cause that icon to display a notification, or identify an icon to modify or delete. Read more on docs.microsoft.com. Type: BOOL Returns TRUE if successful, or FALSE otherwise. If dwMessage is set to NIM_SETVERSION, the function returns TRUE if the version was successfully changed, or FALSE if the requested version is not supported. As of Windows 2000 (Shell32.dll version 5.0), if you set the uVersion member of the NOTIFYICONDATA structure pointed to by lpdata to NOTIFYICON_VERSION_4 or higher, Shell_NotifyIcon mouse and keyboard events are handled differently than in earlier versions of Windows. The differences include the following: This doc was truncated. Read more on docs.microsoft.com.

Destroys an icon and frees any memory the icon occupied.

Type: HICON A handle to the icon to be destroyed. The icon must not be in use. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. It is only necessary to call DestroyIcon for icons and cursors created with the following functions: CreateIconFromResourceEx (if called without the LR_SHARED flag), CreateIconIndirect, and CopyIcon. Do not use this function to destroy a shared icon. A shared icon is valid as long as the module from which it was loaded remains in memory. The following functions obtain a shared icon. This doc was truncated. Read more on docs.microsoft.com.

Calls the default window procedure to provide default processing for any window messages that an application does not process. (Unicode)

Type: HWND A handle to the window procedure that received the message. Read more on docs.microsoft.com. Type: UINT The message. Read more on docs.microsoft.com. Type: WPARAM Additional message information. The content of this parameter depends on the value of the Msg parameter. Read more on docs.microsoft.com. Type: LPARAM Additional message information. The content of this parameter depends on the value of the Msg parameter. Read more on docs.microsoft.com. Type: LRESULT The return value is the result of the message processing and depends on the message. > [!NOTE] > The winuser.h header defines DefWindowProc as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see [Conventions for Function Prototypes](/windows/win32/intl/conventions-for-function-prototypes). Read more on docs.microsoft.com.

Destroys a cursor and frees any memory the cursor occupied. Do not use this function to destroy a shared cursor.

Type: HCURSOR A handle to the cursor to be destroyed. The cursor must not be in use. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. The DestroyCursor function destroys a nonshared cursor. Do not use this function to destroy a shared cursor. A shared cursor is valid as long as the module from which it was loaded remains in memory. The following functions obtain a shared cursor: This doc was truncated. Read more on docs.microsoft.com.

Registers a window class for subsequent use in calls to the CreateWindow or CreateWindowEx function. (RegisterClassExW)

Type: ATOM If the function succeeds, the return value is a class atom that uniquely identifies the class being registered. This atom can only be used by the CreateWindow, CreateWindowEx, GetClassInfo, GetClassInfoEx, FindWindow, FindWindowEx, and UnregisterClass functions and the IActiveIMMap::FilterClientWindows method. If the function fails, the return value is zero. To get extended error information, call GetLastError. If you register the window class by using RegisterClassExA, the application tells the system that the windows of the created class expect messages with text or character parameters to use the ANSI character set; if you register it by using RegisterClassExW, the application requests that the system pass text parameters of messages as Unicode. The IsWindowUnicode function enables applications to query the nature of each window. For more information on ANSI and Unicode functions, see Conventions for Function Prototypes. All window classes that an application registers are unregistered when it terminates. No window classes registered by a DLL are unregistered when the DLL is unloaded. A DLL must explicitly unregister its classes when it is unloaded. Read more on docs.microsoft.com.

Defines a new window message that is guaranteed to be unique throughout the system. The message value can be used when sending or posting messages. (Unicode)

Type: LPCTSTR The message to be registered. Read more on docs.microsoft.com. Type: UINT If the message is successfully registered, the return value is a message identifier in the range 0xC000 through 0xFFFF. If the function fails, the return value is zero. To get extended error information, call GetLastError. The RegisterWindowMessage function is typically used to register messages for communicating between two cooperating applications. If two different applications register the same message string, the applications return the same message value. The message remains registered until the session ends. Only use RegisterWindowMessage when more than one application must process the same message. For sending private messages within a window class, an application can use any integer in the range WM_USER through 0x7FFF. (Messages in this range are private to a window class, not to an application. For example, predefined control classes such as BUTTON, EDIT, LISTBOX, and COMBOBOX may use values in this range.) Read more on docs.microsoft.com.

Destroys the specified menu and frees any memory that the menu occupies.

Type: HMENU A handle to the menu to be destroyed. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. Before closing, an application must use the DestroyMenu function to destroy a menu not assigned to a window. A menu that is assigned to a window is automatically destroyed when the application closes. DestroyMenu is recursive, that is, it will destroy the menu and all its submenus. Read more on docs.microsoft.com.

Creates an overlapped, pop-up, or child window with an extended window style; otherwise, this function is identical to the CreateWindow function. (Unicode)

Type: DWORD The extended window style of the window being created. For a list of possible values, see Extended Window Styles. Read more on docs.microsoft.com. Type: LPCTSTR A null-terminated string or a class atom created by a previous call to the RegisterClass or RegisterClassEx function. The atom must be in the low-order word of lpClassName; the high-order word must be zero. If lpClassName is a string, it specifies the window class name. The class name can be any name registered with RegisterClass or RegisterClassEx, provided that the module that registers the class is also the module that creates the window. The class name can also be any of the predefined system class names. Read more on docs.microsoft.com. Type: LPCTSTR The window name. If the window style specifies a title bar, the window title pointed to by lpWindowName is displayed in the title bar. When using CreateWindow to create controls, such as buttons, check boxes, and static controls, use lpWindowName to specify the text of the control. When creating a static control with the SS_ICON style, use lpWindowName to specify the icon name or identifier. To specify an identifier, use the syntax "#num". Read more on docs.microsoft.com. Type: DWORD The style of the window being created. This parameter can be a combination of the window style values, plus the control styles indicated in the Remarks section. Read more on docs.microsoft.com. Type: int The initial horizontal position of the window. For an overlapped or pop-up window, the x parameter is the initial x-coordinate of the window's upper-left corner, in screen coordinates. For a child window, x is the x-coordinate of the upper-left corner of the window relative to the upper-left corner of the parent window's client area. If x is set to CW_USEDEFAULT, the system selects the default position for the window's upper-left corner and ignores the y parameter. CW_USEDEFAULT is valid only for overlapped windows; if it is specified for a pop-up or child window, the x and y parameters are set to zero. Read more on docs.microsoft.com. Type: int The initial vertical position of the window. For an overlapped or pop-up window, the y parameter is the initial y-coordinate of the window's upper-left corner, in screen coordinates. For a child window, y is the initial y-coordinate of the upper-left corner of the child window relative to the upper-left corner of the parent window's client area. For a list box y is the initial y-coordinate of the upper-left corner of the list box's client area relative to the upper-left corner of the parent window's client area. If an overlapped window is created with the WS_VISIBLE style bit set and the x parameter is set to CW_USEDEFAULT, then the y parameter determines how the window is shown. If the y parameter is CW_USEDEFAULT, then the window manager calls ShowWindow with the SW_SHOW flag after the window has been created. If the y parameter is some other value, then the window manager calls ShowWindow with that value as the nCmdShow parameter. Read more on docs.microsoft.com. Type: int The width, in device units, of the window. For overlapped windows, nWidth is the window's width, in screen coordinates, or CW_USEDEFAULT. If nWidth is CW_USEDEFAULT, the system selects a default width and height for the window; the default width extends from the initial x-coordinates to the right edge of the screen; the default height extends from the initial y-coordinate to the top of the icon area. CW_USEDEFAULT is valid only for overlapped windows; if CW_USEDEFAULT is specified for a pop-up or child window, the nWidth and nHeight parameter are set to zero. Read more on docs.microsoft.com. Type: int The height, in device units, of the window. For overlapped windows, nHeight is the window's height, in screen coordinates. If the nWidth parameter is set to CW_USEDEFAULT, the system ignores nHeight. Read more on docs.microsoft.com. Type: HWND A handle to the parent or owner window of the window being created. To create a child window or an owned window, supply a valid window handle. This parameter is optional for pop-up windows. To create a message-only window, supply HWND_MESSAGE or a handle to an existing message-only window. Read more on docs.microsoft.com. Type: HMENU A handle to a menu, or specifies a child-window identifier, depending on the window style. For an overlapped or pop-up window, hMenu identifies the menu to be used with the window; it can be NULL if the class menu is to be used. For a child window, hMenu specifies the child-window identifier, an integer value used by a dialog box control to notify its parent about events. The application determines the child-window identifier; it must be unique for all child windows with the same parent window. Read more on docs.microsoft.com. Type: HINSTANCE A handle to the instance of the module to be associated with the window. Read more on docs.microsoft.com. Type: LPVOID Pointer to a value to be passed to the window through the CREATESTRUCT structure (lpCreateParams member) pointed to by the lParam param of the WM_CREATE message. This message is sent to the created window by this function before it returns. If an application calls CreateWindow to create a MDI client window, lpParam should point to a CLIENTCREATESTRUCT structure. If an MDI client window calls CreateWindow to create an MDI child window, lpParam should point to a MDICREATESTRUCT structure. lpParam may be NULL if no additional data is needed. Read more on docs.microsoft.com. Type: HWND If the function succeeds, the return value is a handle to the new window. If the function fails, the return value is NULL. To get extended error information, call GetLastError. This function typically fails for one of the following reasons: This doc was truncated. The CreateWindowEx function sends WM_NCCREATE, WM_NCCALCSIZE, and WM_CREATE messages to the window being created. If the created window is a child window, its default position is at the bottom of the Z-order. If the created window is a top-level window, its default position is at the top of the Z-order (but beneath all topmost windows unless the created window is itself topmost). For information on controlling whether the Taskbar displays a button for the created window, see Managing Taskbar Buttons. For information on removing a window, see the DestroyWindow function. The following predefined control classes can be specified in the lpClassName parameter. Note the corresponding control styles you can use in the dwStyle parameter. This doc was truncated. Read more on docs.microsoft.com.

Destroys the specified window.

Type: HWND A handle to the window to be destroyed. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. A thread cannot use DestroyWindow to destroy a window created by a different thread. If the window being destroyed is a child window that does not have the WS_EX_NOPARENTNOTIFY style, a WM_PARENTNOTIFY message is sent to the parent. Read more on docs.microsoft.com.

Retrieves the position of the mouse cursor, in screen coordinates.

Type: LPPOINT A pointer to a POINT structure that receives the screen coordinates of the cursor. Read more on docs.microsoft.com. Type: BOOL Returns nonzero if successful or zero otherwise. To get extended error information, call GetLastError. The cursor position is always specified in screen coordinates and is not affected by the mapping mode of the window that contains the cursor. The calling process must have WINSTA_READATTRIBUTES access to the window station. The input desktop must be the current desktop when you call GetCursorPos. Call OpenInputDesktop to determine whether the current desktop is the input desktop. If it is not, call SetThreadDesktop with the HDESK returned by OpenInputDesktop to switch to that desktop. Read more on docs.microsoft.com.

Brings the thread that created the specified window into the foreground and activates the window.

Type: HWND A handle to the window that should be activated and brought to the foreground. Read more on docs.microsoft.com. Type: BOOL If the window was brought to the foreground, the return value is nonzero. If the window was not brought to the foreground, the return value is zero. The system restricts which processes can set the foreground window. A process can set the foreground window by calling **SetForegroundWindow** only if: - All of the following conditions are true: - The calling process belongs to a desktop application, not a UWP app or a Windows Store app designed for Windows 8 or 8.1. - The foreground process has not disabled calls to **SetForegroundWindow** by a previous call to the [**LockSetForegroundWindow**](nf-winuser-locksetforegroundwindow.md) function. - The foreground lock time-out has expired (see [**SPI_GETFOREGROUNDLOCKTIMEOUT** in **SystemParametersInfo**](nf-winuser-systemparametersinfoa.md#SPI_GETFOREGROUNDLOCKTIMEOUT)). - No menus are active. - Additionally, at least one of the following conditions is true: - The calling process is the foreground process. - The calling process was started by the foreground process. - There is currently no foreground window, and thus no foreground process. - The calling process received the last input event. - Either the foreground process or the calling process is being debugged. It is possible for a process to be denied the right to set the foreground window even if it meets these conditions. An application cannot force a window to the foreground while the user is working with another window. Instead, Windows flashes the taskbar button of the window to notify the user. A process that can set the foreground window can enable another process to set the foreground window by calling the [**AllowSetForegroundWindow**](nf-winuser-allowsetforegroundwindow.md) function. The process specified by the *dwProcessId* parameter to **AllowSetForegroundWindow** loses the ability to set the foreground window the next time that either the user generates input, unless the input is directed at that process, or the next time a process calls **AllowSetForegroundWindow**, unless the same process is specified as in the previous call to **AllowSetForegroundWindow**. The foreground process can disable calls to SetForegroundWindow by calling the [**LockSetForegroundWindow**](nf-winuser-locksetforegroundwindow.md) function. Read more on docs.microsoft.com.

Creates a drop-down menu, submenu, or shortcut menu.

Type: HMENU If the function succeeds, the return value is a handle to the newly created menu. If the function fails, the return value is NULL. To get extended error information, call GetLastError. The application can add the new menu to an existing menu, or it can display a shortcut menu by calling the TrackPopupMenuEx or TrackPopupMenu functions. Resources associated with a menu that is assigned to a window are freed automatically. If the menu is not assigned to a window, an application must free system resources associated with the menu before closing. An application frees menu resources by calling the DestroyMenu function. Read more on docs.microsoft.com.

Inserts a new menu item at the specified position in a menu. (Unicode)

Type: HMENU A handle to the menu in which the new menu item is inserted. Read more on docs.microsoft.com. Type: UINT The identifier or position of the menu item before which to insert the new item. The meaning of this parameter depends on the value of fByPosition. Read more on docs.microsoft.com. Type: BOOL Controls the meaning of item. If this parameter is FALSE, item is a menu item identifier. Otherwise, it is a menu item position. See Accessing Menu Items Programmatically for more information. Read more on docs.microsoft.com. Type: LPCMENUITEMINFO A pointer to a MENUITEMINFO structure that contains information about the new menu item. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, use the GetLastError function. The application must call the DrawMenuBar function whenever a menu changes, whether the menu is in a displayed window. In order for keyboard accelerators to work with bitmap or owner-drawn menu items, the owner of the menu must process the WM_MENUCHAR message. See Owner-Drawn Menus and the WM_MENUCHAR Message for more information. Read more on docs.microsoft.com.

Appends a new item to the end of the specified menu bar, drop-down menu, submenu, or shortcut menu. You can use this function to specify the content, appearance, and behavior of the menu item. (Unicode)

Type: HMENU A handle to the menu bar, drop-down menu, submenu, or shortcut menu to be changed. Read more on docs.microsoft.com. Type: UINT Type: UINT_PTR The identifier of the new menu item or, if the uFlags parameter is set to MF_POPUP, a handle to the drop-down menu or submenu. Read more on docs.microsoft.com. Type: LPCTSTR The content of the new menu item. The interpretation of lpNewItem depends on whether the uFlags parameter includes the following values. This doc was truncated. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. The application must call the DrawMenuBar function whenever a menu changes, whether the menu is in a displayed window. To get keyboard accelerators to work with bitmap or owner-drawn menu items, the owner of the menu must process the WM_MENUCHAR message. For more information, see Owner-Drawn Menus and the WM_MENUCHAR Message. The following groups of flags cannot be used together: This doc was truncated. Read more on docs.microsoft.com.

Displays a shortcut menu at the specified location and tracks the selection of items on the shortcut menu. The shortcut menu can appear anywhere on the screen.

Type: HMENU A handle to the shortcut menu to be displayed. This handle can be obtained by calling the CreatePopupMenu function to create a new shortcut menu or by calling the GetSubMenu function to retrieve a handle to a submenu associated with an existing menu item. Read more on docs.microsoft.com. Type: UINT Specifies function options. Use one of the following flags to specify how the function positions the shortcut menu horizontally. This doc was truncated. Read more on docs.microsoft.com. Type: int The horizontal location of the shortcut menu, in screen coordinates. Read more on docs.microsoft.com. Type: int The vertical location of the shortcut menu, in screen coordinates. Read more on docs.microsoft.com. Type: HWND A handle to the window that owns the shortcut menu. This window receives all messages from the menu. The window does not receive a WM_COMMAND message from the menu until the function returns. If you specify TPM_NONOTIFY in the fuFlags parameter, the function does not send messages to the window identified by hwnd. However, you must still pass a window handle in hwnd. It can be any window handle from your application. Read more on docs.microsoft.com. Type: LPTPMPARAMS A pointer to a TPMPARAMS structure that specifies an area of the screen the menu should not overlap. This parameter can be NULL. Read more on docs.microsoft.com. Type: BOOL If you specify TPM_RETURNCMD in the fuFlags parameter, the return value is the menu-item identifier of the item that the user selected. If the user cancels the menu without making a selection, or if an error occurs, the return value is zero. If you do not specify TPM_RETURNCMD in the fuFlags parameter, the return value is nonzero if the function succeeds and zero if it fails. To get extended error information, call GetLastError. Call GetSystemMetrics with SM_MENUDROPALIGNMENT to determine the correct horizontal alignment flag (TPM_LEFTALIGN or TPM_RIGHTALIGN) and/or horizontal animation direction flag (TPM_HORPOSANIMATION or TPM_HORNEGANIMATION) to pass to TrackPopupMenu or TrackPopupMenuEx. This is essential for creating an optimal user experience, especially when developing Microsoft Tablet PC applications. To display a context menu for a notification icon, the current window must be the foreground window before the application calls TrackPopupMenu or TrackPopupMenuEx. Otherwise, the menu will not disappear when the user clicks outside of the menu or the window that created the menu (if it is visible). If the current window is a child window, you must set the (top-level) parent window as the foreground window. Read more on docs.microsoft.com.

Returns the dots per inch (dpi) value for the specified window.

The window that you want to get information about. The DPI for the window, which depends on the [DPI_AWARENESS](/windows/win32/api/windef/ne-windef-dpi_awareness) of the window. See the **Remarks** section for more information. An invalid *hwnd* value will result in a return value of 0. The following table indicates the return value of GetDpiForWindow based on the [DPI_AWARENESS](/windows/win32/api/windef/ne-windef-dpi_awareness) of the provided *hwnd*. This doc was truncated. Read more on docs.microsoft.com.

Retrieves the specified system metric or system configuration setting taking into account a provided DPI.

The system metric or configuration setting to be retrieved. See GetSystemMetrics for the possible values. The DPI to use for scaling the metric. If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. This function returns the same result as GetSystemMetrics but scales it according to an arbitrary DPI you provide if appropriate.

Places (posts) a message in the message queue associated with the thread that created the specified window and returns without waiting for the thread to process the message. (Unicode)

Type: HWND A handle to the window whose window procedure is to receive the message. The following values have special meanings. This doc was truncated. Read more on docs.microsoft.com. Type: UINT The message to be posted. For lists of the system-provided messages, see System-Defined Messages. Read more on docs.microsoft.com. Type: WPARAM Additional message-specific information. Read more on docs.microsoft.com. Type: LPARAM Additional message-specific information. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. When a message is blocked by UIPI the last error, retrieved with GetLastError, is set to 5 (access denied). Messages in a message queue are retrieved by calls to the GetMessage or PeekMessage function. Applications that need to communicate using HWND_BROADCAST should use the RegisterWindowMessage function to obtain a unique message for inter-application communication. The system only does marshalling for system messages (those in the range 0 to (WM_USER-1)). To send other messages (those >= WM_USER) to another process, you must do custom marshalling. If you send a message in the range below WM_USER to the asynchronous message functions (PostMessage, SendNotifyMessage, and SendMessageCallback), its message parameters cannot include pointers. Otherwise, the operation will fail. The functions will return before the receiving thread has had a chance to process the message and the sender will free the memory before it is used. Do not post the WM_QUIT message using PostMessage; use the PostQuitMessage function. An accessibility application can use PostMessage to post WM_APPCOMMAND messages to the shell to launch applications. This functionality is not guaranteed to work for other types of applications. There is a limit of 10,000 posted messages per message queue. This limit should be sufficiently large. If your application exceeds the limit, it should be redesigned to avoid consuming so many system resources. To adjust this limit, modify the following registry key.

HKEY_LOCAL_MACHINE SOFTWARE Microsoft Windows NT CurrentVersion Windows USERPostMessageLimit

If the function fails, call GetLastError to get extended error information. GetLastError returns ERROR_NOT_ENOUGH_QUOTA when the limit is hit. The minimum acceptable value is 4000. Read more on docs.microsoft.com.

Determines whether a window is maximized.

Type: HWND A handle to the window to be tested. Read more on docs.microsoft.com. Type: BOOL If the window is zoomed, the return value is nonzero. If the window is not zoomed, the return value is zero. Learn more about this API from docs.microsoft.com.

Retrieves the dimensions of the bounding rectangle of the specified window. The dimensions are given in screen coordinates that are relative to the upper-left corner of the screen.

Type: HWND A handle to the window. Read more on docs.microsoft.com. Type: LPRECT A pointer to a RECT structure that receives the screen coordinates of the upper-left and lower-right corners of the window. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError. In conformance with conventions for the RECT structure, the bottom-right coordinates of the returned rectangle are exclusive. In other words, the pixel at (right, bottom) lies immediately outside the rectangle. GetWindowRect is virtualized for DPI. In Windows Vista and later, the Window Rect now includes the area occupied by the drop shadow. Calling GetWindowRect will have different behavior depending on whether the window has ever been shown or not. If the window has not been shown before, GetWindowRect will not include the area of the drop shadow. To get the window bounds excluding the drop shadow, use DwmGetWindowAttribute, specifying DWMWA_EXTENDED_FRAME_BOUNDS. Note that unlike the Window Rect, the DWM Extended Frame Bounds are not adjusted for DPI. Getting the extended frame bounds can only be done after the window has been shown at least once. Read more on docs.microsoft.com.

Calculates an appropriate pop-up window position using the specified anchor point, pop-up window size, flags, and the optional exclude rectangle.

Type: const POINT* The specified anchor point. Read more on docs.microsoft.com. Type: const SIZE* The specified window size. Read more on docs.microsoft.com. Type: UINT Use one of the following flags to specify how the function positions the pop-up window horizontally and vertically. The flags are the same as the vertical and horizontal positioning flags of the TrackPopupMenuEx function. Use one of the following flags to specify how the function positions the pop-up window horizontally. This doc was truncated. Read more on docs.microsoft.com. Type: RECT* A pointer to a structure that specifies the exclude rectangle. It can be NULL. Read more on docs.microsoft.com. Type: RECT* A pointer to a structure that specifies the pop-up window position. Read more on docs.microsoft.com. Type: BOOL If the function succeeds, it returns TRUE; otherwise, it returns FALSE. To get extended error information, call GetLastError. TPM_WORKAREA is supported for the TrackPopupMenu and TrackPopupMenuEx functions.

The MonitorFromPoint function retrieves a handle to the display monitor that contains a specified point.

A POINT structure that specifies the point of interest in virtual-screen coordinates. Determines the function's return value if the point is not contained within any display monitor. If the point is contained by a display monitor, the return value is an HMONITOR handle to that display monitor. If the point is not contained by a display monitor, the return value depends on the value of dwFlags. Learn more about this API from docs.microsoft.com.