检查程序是否重复打开,若重复打开只接最大化第一次打开程序

function CheckSingleApp(): Boolean;
  var
    MutexHandler: HWND;
    Pid: HWND;
  begin
    result:= true;
    MutexHandler:= CreateMutex(nil, True,PWideChar(ExtractFileName(Application.ExeName)));
    if GetLastError= ERROR_ALREADY_EXISTS then begin
      ReleaseMutex(MutexHandler);
      Pid:= FindWindow(nil,PChar('WMS'));
      if Pid>0 then begin
        ShowWindow(Pid,SW_SHOWMAXIMIZED);
      end else begin
        Application.MessageBox(PChar('程序已打开,请勿重复打开.'),'提示',mb_ok+ MB_ICONWARNING);
      end;
      Application.Terminate;
    end;
  end;