GetTopWindow function (winuser.h)

Examines the Z order of the child windows associated with the specified parent window and retrieves a handle to the child window at the top of the Z order.

Syntax

HWND GetTopWindow(
  [in, optional] HWND hWnd
);

Parameters

[in, optional] hWnd

Type: HWND

A handle to the parent window whose child windows are to be examined. If this parameter is NULL, the function returns a handle to the window at the top of the Z order.

Return value

Type: HWND

If the function succeeds, the return value is a handle to the child window at the top of the Z order. If the specified window has no child windows, the return value is NULL. To get extended error information, use the GetLastError function.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [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-l1-1-4 (introduced in Windows 10, version 10.0.14393)

See also

Conceptual

GetNextWindow

GetWindow

Reference

Windows