本实例将实现一个可动态更新的绘图菜单，当满足一定条件时，会打开或折叠部分菜单项

程序功能说明：当[固定大小]菜单项被选中时，相应的几项菜单也被显示。用户选择好大小和图形（是椭圆，还是矩形），在窗口中单击鼠标左键，将绘制相应的图形。

当[自定义大小]菜单项被选中时，则几个提供固定大小的菜单项被移去。用户选择图形（是椭圆还是矩形后），在窗口中按住鼠标左键并托动，程序将绘制相应图形。



-example of the realization of a dynamic update of the graphics menu, when they meet certain conditions, we will open or folding some menu items procedures Descr iption : When the [fixed size] menu item selected, the corresponding number of the menu are shown. Users select the right size and graphics (yes oval, or rectangle), in the window by clicking the left mouse button will draw the corresponding graphics. When [custom size] menu item was selected, then several fixed-size menu items were removed. Users choose graphics (yes oval or rectangular), this in the window to press the left mouse button and moving care, the program will draw the corresponding graphics.