支持用户利用鼠标创建和删除2维多边形对象。基本功能包括：

对象创建：支持用户利用鼠标指定各个顶点位置，创建多边形。

对象删除： 支持用户选择一个多边形（与你的多边形保存的数据结构有关）并删除。

对象存储： 设计一种数据结构存储每个多边形的顶点与边，支持文件存盘，。

支持用户选择多边形的颜色

支持用户移动多边形

支持用户改变多边形单个顶点的位置-Support for the user to use the mouse to create and delete a 2-dimensional polygon object. Basic features include: object creation: support for users to use the mouse to specify each vertex position, and create a polygon. The object deletion: support for the user to select a polygon (saved with your polygon data structure) and delete. Object storage: design a data structure that stores each polygon vertices and edges, support for file archiving. Support for the user to select the color of the polygon to support the user moves the polygon support the user to change the position of the polygon a single vertex