采用设计模式，设计图形编辑器，能够实现图形的绘画，选择，图形的简单操作，以及文件的保存、打开等功能。-Design patterns, design graphics editor, able to achieve graphics painting, choose the simple operation of the graphics, as well as to save the file open function.

CAD的简单功能实现和重要的程序设计模式-Simple functions and important application of CAD design patterns

使用三种设计模式写的一个画图小工具，功能比较简单，但功能不是最重要的，关键是在使用设计模式的过程中体会设计模式在软件开发中所起的作用。-Three a drawing gadget design patterns written, function is relatively simple, but the function is not the most important, the key is the experience of design pattern in software dev