AllowSetForegroundWindow function (winuser.h)

Enables the specified process to set the foreground window using the SetForegroundWindow function. The calling process must already be able to set the foreground window. For more information, see Remarks later in this topic.

BOOL AllowSetForegroundWindow(
  [in] DWORD dwProcessId
);

[in] dwProcessId

Type: DWORD

The identifier of the process that will be enabled to set the foreground window. If this parameter is ASFW_ANY, all processes will be enabled to set the foreground window.

Type: BOOL

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. The function will fail if the calling process cannot set the foreground window. To get extended error information, call GetLastError.

The system restricts which processes can set the foreground window. Normally, a process can set the foreground window by calling the SetForegroundWindow function 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 function.
  • The foreground lock time-out has expired (see SPI_GETFOREGROUNDLOCKTIMEOUT in SystemParametersInfo).
  • 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.

A process that can set the foreground window can enable another process to set the foreground window by calling AllowSetForegroundWindow. The process specified by the dwProcessId parameter 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.

Conceptual

LockSetForegroundWindow

Reference

SetForegroundWindow

Windows