Determining the Topmost Pop-Up Window

• Microsoft Windows Software Development Kit (SDK) versions 3.0 and 3.1
• Microsoft Win32 Application Programming Interface (API) included with:

      - Microsoft Windows NT versions 3.5 and 3.51
      - Microsoft Windows 95 version 4.0
  

When an application has many pop-up child windows (with a common parent window), the GetNextWindow() function can be used when one pop-up window is closed to determine the next topmost pop-up window that remains.

The following code fragment shows a window procedure for simple pop-up windows (modified from the PARTY program in Petzold's "Programming Windows"). In the WM_CLOSE case, the handle received by the pop-up window procedure is the handle of the pop-up to be closed. This sample activates the topmost pop-up window that remains by giving it the focus.

long FAR PASCAL PopupWndProc (hWnd, iMessage, wParam, lParam)

     HWND     hWnd;
     unsigned iMessage;
     WORD     wParam;
     LONG     lParam;
     {
     HWND     hWndPopup;

     switch (iMessage)
        {
        case WM_CLOSE:
            hWndPopup = GetNextWindow(hWnd, GW_HWNDNEXT);
            if (hWndPopup)
                SetFocus(hWndPopup);
            break;
        }

     return DefWindowProc (hWnd, iMessage, wParam, lParam) ;
     }

For additional information on changing the Z-order of an MDI window, query on the following words in the Microsoft Knowledge Base: