该代码提供了很好的类型buttonST类的按钮类，中包含位图按钮，图标按钮，三态按钮，check按钮等，可以绘制按钮背景-the code provides a very excellent button class named buttonST, including bitmap-button, icon-button, three-statements-button, check-button and so on.You can specified your button backgroun