用VB编的画圆的方法，简单易懂，大家下来看看吧！-Drawcircle with VB series approach, easy to understand, let everybody look down!

圆图元类，包含基本属性，实现画圆功能和平移、旋转等多种图形操作-Circular pixel type, including the basic properties of functions and the achievement of drawcircle translation, rotation and many other graphics operations

直线裁剪算法画圆算法 -Linear cutting algorithm drawcircle