SetWindowDisplayAffinity function (winuser.h)

Specifies where the content of the window can be displayed.

Syntax

BOOL SetWindowDisplayAffinity(
  HWND  hWnd,
  DWORD dwAffinity
);

Parameters

hWnd

Type: HWND

A handle to the top-level window. The window must belong to the current process.

dwAffinity

Type: DWORD

The display affinity setting that specifies where the content of the window can be displayed.

This parameter can be one of the following values.

Value Meaning
WDA_NONE
0x00000000
Imposes no restrictions on where the window can be displayed.
WDA_MONITOR
0x00000001
The window content is displayed only on a monitor. Everywhere else, the window appears with no content.
WDA_EXCLUDEFROMCAPTURE
0x00000011
The window is displayed only on a monitor. Everywhere else, the window does not appear at all.

One use for this affinity is for windows that show video recording controls, so that the controls are not included in the capture.

Introduced in Windows 10 Version 2004. See remarks about compatibility regarding previous versions of Windows.

Return value

Type: BOOL

If the function succeeds, it returns TRUE; otherwise, it returns FALSE when, for example, the function call is made on a non top-level window. To get extended error information, call GetLastError.

Remarks

This function and GetWindowDisplayAffinity are designed to support the window content protection feature that is new to Windows 7. This feature enables applications to protect their own onscreen window content from being captured or copied through a specific set of public operating system features and APIs. However, it works only when the Desktop Window Manager(DWM) is composing the desktop.

It is important to note that unlike a security feature or an implementation of Digital Rights Management (DRM), there is no guarantee that using SetWindowDisplayAffinity and GetWindowDisplayAffinity, and other necessary functions such as DwmIsCompositionEnabled, will strictly protect windowed content, for example where someone takes a photograph of the screen.

Starting in Windows 10 Version 2004, WDA_EXCLUDEFROMCAPTURE is a supported value. Setting the display affinity to WDA_EXCLUDEFROMCAPTURE on previous version of Windows will behave as if WDA_MONITOR is applied.

Requirements

   
Minimum supported client Windows 7 [desktop apps only]
Minimum supported server Windows Server 2008 R2 [desktop apps only]
Target Platform Windows
Header winuser.h (include Windows.h)
Library User32.lib
DLL User32.dll
API set ext-ms-win-ntuser-window-l1-1-1 (introduced in Windows 8.1)

See also

SetWindowDisplayAffinity, Windows