Fix #151 and a crash bug related to sub frameless window

Sine Striker

2024-11-21 c3ef42dad254f6d04cab521c9ae619a46bb84f7a

 examples/mainwindow/mainwindow.h

@@ -30,8 +30,6 @@
protected:
    bool event(QEvent *event) override;

    void closeEvent(QCloseEvent *event) override;

private:
    void installWindowAgent();
    void loadStyleSheet(Theme theme);