CDC SaveDC保存的问题
大家好，
我记得 OnPain 里是不需要调用SaveDC。好像CPaintDC 已经调用过了 SaveDC，但今天跟了一下代码，没有发现有调用SaveDC,
记不清楚了，不知道有没有哪位记得是哪个（ClientDC, PaintDC,WindowDC)里不需要调用SaveDC?
[解决办法]
MSND:
Saves the current state of the device context by copying state information (such as clipping region, selected objects, and mapping mode) to a context stack maintained by Windows. The saved device context can later be restored by using RestoreDC.
[解决办法]
保存当前的设备上下文信息。将状态（如剪切区、选中的对象、映射模式）拷贝到Windows负责保存的栈中。使用RestoreDC可以恢复保存的设备上下文。
http://wmnmtm.blog.163.com/blog/static/3824571420111912310476/
[解决办法]
试试：
CS_OWNDC
[解决办法]
双缓存绘图我一般先 SaveDC
