feat: Repaint the skin of a custom control, and the painting is complete

MyStyle has completed, QStylePainter's inheritance rewrite has not yet started

QtMyStyleEx/QtExample03/QtStyleEx/myswitchbutton.h

@@ -0,0 +1,29 @@
+#ifndef MYSWITCHBUTTON_H
+#define MYSWITCHBUTTON_H
+
+#include <QAbstractButton>
+class QStyleOptionButton;
+
+class MySwitchButtonPrivate;
+class MySwitchButton : public QAbstractButton//bianxinagjicengle QObject
+{
+    Q_OBJECT
+public:
+    explicit MySwitchButton(QWidget* parent = nullptr);
+    ~MySwitchButton();
+
+    // QWidget interface
+public:
+    virtual QSize sizeHint() const override;
+
+protected:
+    virtual void paintEvent(QPaintEvent *event) override;
+
+private:
+    void initStyleOption(QStyleOptionButton *opt) const;
+
+private:
+    Q_DECLARE_PRIVATE(MySwitchButton)
+};
+
+#endif // MYSWITCHBUTTON_H