在开始一个路径前,先调用CDC类的成员函数BeginPath,然后调用一系列的输出函数,在完成绘制后,再调用CDC类的成员函数,在完成一个路径之后,就可以调用StrokePath来绘制该路径,这就是路径的基本用法.-at the beginning of a path, first call CDC category of members BeginPath function, then called a series of the output function, the complete mapping and then call CDC category of members function, the completion of a path, we can call StrokePath to mapping the path, This is the path the basic usage.