SetWindowDisplayAffinity function

Stores the display affinity setting in kernel mode on the hWnd associated with the window.

Syntax

BOOL WINAPI SetWindowDisplayAffinity(
  _In_ HWND  hWnd,
  _In_ DWORD dwAffinity
);

Parameters

hWnd [in]

Type: HWND

A handle to the window.

dwAffinity [in]

Type: DWORD

The display affinity setting. This setting specifies where the window's contents are can be displayed. Set this value to WDA_MONITOR to display the window's contents only on a monitor. Set this value to WDA_NONE to remove the monitor-only affinity.

Return value

Type:

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.

Requirements

See also

Reference

SetWindowDisplayAffinity

Conceptual

Windows