An application can move a window to the top or bottom of the z-order by passing the SWP_ZORDER constant to the WinSetWindowPos function. An application specifies where to move the window by specifying the HWND_TOP or HWND_BOTTOM constants.

The code fragment in the following figure uses WinSetWindowPos to change the z-order of a window.

    HWND hwndParent;
    HWND hwndNext;
    HENUM henum;

        WinSetWindowPos(
            hwndNext,       /* Next window to move  */
            HWND_TOP,       /* Put window on top    */
            0, 0, 0, 0,     /* Not used for z-order */
            SWP_ZORDER);    /* Change z-order       */

An application also can specify the window that the given window is to move behind. In this case, the application specifies the window handle instead of the HWND_TOP or HWND_BOTTOM constant.

    HWND hwndParent;
    HWND hwndNext;
    HWND hwndExchange;
    HENUM henum;

    henum = WinBeginEnumWindows(hwndParent);

    hwndExchange = WinGetNextWindow(henum);

                        /* hwndNext has top window;
            hwndExchange has window under the top. */

    WinSetWindowPos(
        hwndNext,       /* Next window to move     */
        hwndExchange,   /* Put lower window on top */
        0, 0, 0, 0,     /* Not used for z-order    */
        SWP_ZORDER);    /* Change z-order          */

    WinEndEnumWindows(henum);