GetWindow

The GetWindow function retrieves a handle to a window that has the specified relationship (Z order or owner) to the specified window.

HWND GetWindow(
  HWND hWnd,  // handle to original window
  UINT uCmd   // relationship flag
);
 

Parameters

hWnd

Handle to a window. The window handle retrieved is relative to this window, based on the value of the uCmd parameter.

uCmd

Specifies the relationship between the specified window and the window whose handle is to be retrieved. This parameter can be one of the following values:

Value	Meaning
GW_CHILD	The retrieved handle identifies the child window at the top of the Z order, if the specified window is a parent window; otherwise, the retrieved handle is NULL. The function examines only child windows of the specified window. It does not examine descendant windows.
GW_ENABLEDPOPUP	Windows NT 5.0 and later: The retrieved handle identifies the enabled popup window owned by the specified window (the search uses the first such window found using GW_HWNDNEXT); otherwise, if there are no enabled popup windows, the retrieved handle is that of the specified window.
GW_HWNDFIRST	The retrieved handle identifies the window of the same type that is highest in the Z order. If the specified window is a topmost window, the handle identifies the topmost window that is highest in the Z order. If the specified window is a top-level window, the handle identifies the top-level window that is highest in the Z order. If the specified window is a child window, the handle identifies the sibling window that is highest in the Z order.
GW_HWNDLAST	The retrieved handle identifies the window of the same type that is lowest in the Z order. If the specified window is a topmost window, the handle identifies the topmost window that is lowest in the Z order. If the specified window is a top-level window, the handle identifies the top-level window that is lowest in the Z order. If the specified window is a child window, the handle identifies the sibling window that is lowest in the Z order.
GW_HWNDNEXT	The retrieved handle identifies the window below the specified window in the Z order. If the specified window is a topmost window, the handle identifies the topmost window below the specified window. If the specified window is a top-level window, the handle identifies the top-level window below the specified window. If the specified window is a child window, the handle identifies the sibling window below the specified window.
GW_HWNDPREV	The retrieved handle identifies the window above the specified window in the Z order. If the specified window is a topmost window, the handle identifies the topmost window above the specified window. If the specified window is a top-level window, the handle identifies the top-level window above the specified window. If the specified window is a child window, the handle identifies the sibling window above the specified window.
GW_OWNER	The retrieved handle identifies the specified window's owner window, if any.

Return Values

If the function succeeds, the return value is a window handle. If no window exists with the specified relationship to the specified window, the return value is NULL. To get extended error information, call GetLastError.

Remarks

The EnumChildWindows function is more reliable than calling GetWindow in a loop. An application that calls GetWindow to perform this task risks being caught in an infinite loop or referencing a handle to a window that has been destroyed.

Windows CE: In Windows CE version 1.0, the GW_OWNER flag value for the uCmd parameter is only supported for dialog boxes.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winuser.h.
  Import Library: Use user32.lib.

See Also

Windows Overview, Window Functions, EnumChildWindows