在对话框中绘图，介绍如何在对话框中绘图。实现绘图操作最重要的一个类就是设备环境类CDC类，该类的成员函数可以实现颜色设置、图形绘制、打印输出等各种操作。-In the dialog box, drawing, drawing in the dialog box shows you how. Drawing operations to achieve the most important class is the class of device context CDC class, class m