Windows 画图程序的白色“画布”实现。主要用到了CRectTracker类来控制窗体的大小，实现出窗体有8个控制点的目的。-white "canvas" to achieve. CRectTracker used in the main control window class size, Form a realization out eight control points purpose.

在vc的环境下,关于bezier曲线的实现,可以用鼠标在屏幕上任意给出控制点的位子,(In the vc environment, on the implementation of the bezier curve, you can use a mouse in the arbitrary control point position is given on the screen,)