这是一个简单的画图程序，能实现画直线与普通画笔一样的画图功能，并能对它们进行任意的裁剪，本人水平有限，程序必存在许多不足，望高人们能多加指点。-This is a simple drawing program, able to draw straight lines with the same brush ordinary drawing capabilities and their arbitrary cut, I limited, and certainly there are many p