学步园

有几种窗口置顶的方法，简单的有：

ShowWindow(窗口句柄,sw_ShowNormal);

SetWindowPos(窗口句柄,HWND_NOTOPMOST,0,0,0,0,SWP_NOMOV OR SWP_NOSIZE OR SWP_SHOWWINDOW);

另一种方式是：

function ForceForegroundWindow(hwnd: THandle): boolean;
const
    SPI_GETFOREGROUNDLOCKTIMEOUT = $2000;
    SPI_SETFOREGROUNDLOCKTIMEOUT = $2001;
var
    ForegroundThreadID: DWORD;
    ThisThreadID      : DWORD;
    timeout           : DWORD;
begin
    if IsIconic(hwnd) then ShowWindow(hwnd, SW_RESTORE);

    // Windows 98/2000 doesn't want to foreground a window when some other
    // window has keyboard focus

    if ((Win32Platform = VER_PLATFORM_WIN32_NT) and (Win32MajorVersion > 4))
        or
        ((Win32Platform = VER_PLATFORM_WIN32_WINDOWS) and
        ((Win32MajorVersion > 4) or ((Win32MajorVersion = 4) and
         (Win32MinorVersion > 0)))) then begin
        // Code from Karl E. Peterson, www.mvps.org/vb/sample.htm
        // Converted to Delphi by Ray Lischner
        // Published in The Delphi Magazine 55, page 16

        Result := false;
        ForegroundThreadID := GetWindowThreadProcessID(GetForegroundWindow,nil);
        ThisThreadID := GetWindowThreadPRocessId(hwnd,nil);
        if AttachThreadInput(ThisThreadID, ForegroundThreadID, true) then begin
            BringWindowToTop(hwnd); // IE 5.5 related hack
            SetForegroundWindow(hwnd);
            AttachThreadInput(ThisThreadID, ForegroundThreadID, false);
            Result := (GetForegroundWindow = hwnd);
        end;

        if not Result then begin
            // Code by Daniel P. Stasinski
            SystemParametersInfo(SPI_GETFOREGROUNDLOCKTIMEOUT, 0, @timeout, 0);
            SystemParametersInfo(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, TObject(0), SPIF_SENDCHANGE);
            BringWindowToTop(hwnd); // IE 5.5 related hack
            SetForegroundWindow(hWnd);
            SystemParametersInfo(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, TObject(timeout), SPIF_SENDCHANGE);
        end;
    end
    else begin
        BringWindowToTop(hwnd); // IE 5.5 related hack
        SetForegroundWindow(hwnd);
    end;

    Result := (GetForegroundWindow = hwnd);
end;

 另外，主窗体有个置顶的属性FormStyle, 设置为fsStayOnTop就可以直接置顶了。