功能:用面向对象的思想来实现了对直线 矩形 椭圆三种图元的绘制 选定 移动 并添加了编辑设置图元多种属性功能 是深入学习GDI编程很好的例子-functions : Object-oriented thinking to achieve a pair of three straight rectangular oval map of the selected mobile mapping and add a map editor Set Attribute function of a varie