Partially finish the bug after window close and reshow

Sine Striker

2024-02-20 2d2fc799bc698ebf7e7c8bcc394366d0d7bf071b

 examples/mainwindow/main.cpp

@@ -1,4 +1,5 @@
// Copyright (C) 2023-2024 Stdware Collections
// Copyright (C) 2023-2024 Stdware Collections (https://www.github.com/stdware)
// Copyright (C) 2021-2023 wangwenx190 (Yuhang Zhao)
// SPDX-License-Identifier: Apache-2.0

#include <QtWidgets/QApplication>
@@ -31,5 +32,8 @@

    MainWindow w;
    w.show();

    QMainWindow w2;
    w2.show();
    return a.exec();
}