fix demo acrylic

Zhao Yuhang

2023-12-23 03c2a26820691493f5ebe86f64e0e360b0561642

 examples/mainwindow/mainwindow.h

@@ -28,6 +28,7 @@

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

    Theme currentTheme{};