利用MFC类库，实现的功能是在对话框中对工具条中的相应按钮做出响应：比如划点，直线，多边形，用指定颜色填充等功能。-Use MFC class library, the realization of the function is in the dialog box on the toolbar button to make the appropriate response: for example, designated points, a straight line, polygon, fi