feat: Build the custom redraw frame, eg: QScrollBar

搭建自定义QStyle重绘的框架，使用系统自带的和滚动条QScrollBar为示范

QtCustomStyleEx/ExCustomStyle.h

@@ -1,18 +1,37 @@
 #ifndef EXCUSTOMSTYLE_H
 #define EXCUSTOMSTYLE_H
 
+//Qt自带的库
 #include <QCommonStyle>
+#include <QPainter>
+#include <QStyleOption>
 
+//自定义的文件或库
 #include "ExDefineGlobal.h"
 
 CUSTOMSTYLE_BEDGIN_NAMESPACE
 
+//一些工具函数:绘画圈,叉,对号,阴影等功能函数
+CUSTOM_BEGIN_NAMESPACE
+CUSTOMSTYLE_END_NAMESPACE
+
 class ExCustomStyle : public QCommonStyle
 {
     Q_OBJECT
 
 public:
     ExCustomStyle();
+
+public:  //重写QCommonStyle重载的函数
+    virtual void drawPrimitive(PrimitiveElement pe, const QStyleOption *opt, QPainter *p, const QWidget *w) const override;
+    virtual void drawControl(ControlElement element, const QStyleOption *opt, QPainter *p, const QWidget *w) const override;
+    virtual QRect subElementRect(SubElement subElement, const QStyleOption *option, const QWidget *widget) const override;
+    virtual int pixelMetric(PixelMetric metric, const QStyleOption *option, const QWidget *widget) const override;
+    virtual QSize sizeFromContents(ContentsType ct, const QStyleOption *opt, const QSize &contentsSize, const QWidget *w) const override;
+    virtual int styleHint(StyleHint stylehint, const QStyleOption *opt, const QWidget *widget, QStyleHintReturn *returnData) const override;
+    virtual QIcon standardIcon(StandardPixmap standardIcon, const QStyleOption *option, const QWidget *widget) const override;
+
+public:
 };
 
 CUSTOMSTYLE_END_NAMESPACE