VC++ 画直线的小例子源码，按住鼠标左键在窗口区向任一方向滑去，即可画出一第直线，重复上述步骤，可画出无限多个直线，暂时不支持画曲线，运行效果如图所示。-The VC++ draw a straight line small example source code, press and hold the left mouse button in the window area slide, in either direction, you can draw a first straight l