//返回值：如果窗口原來可見，返回值為非零；如果函數原來被隱藏，返回值為零。
private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);
//API 常數定義
private const int SW_HIDE = 0;
private const int SW_NORMAL = 1; //正常彈出窗體
private const int SW_MAXIMIZE = 3; //最大化彈出窗體
private const int SW_SHOWNOACTIVATE = 4;
private const int SW_SHOW = 5;
private const int SW_MINIMIZE = 6;
private const int SW_RESTORE = 9;
private const int SW_SHOWDEFAULT = 10;
ShowWindowAsync(instance.MainWindowHandle, SW_RESTORE);
SetForegroundWindow(instance.MainWindowHandle);