VC++ CString.Format 變數參數不可代自己

参考MSDN如下:
The call will fail if the string object itself is offered as a parameter to Format. For example, the following code:

CString str = "Some Data";
str.Format(_T("%s%d"), str, 123) ); // Attention: str is also used in the parameter list.
causes unpredictable results.

今天也遇到了，CString自己format自己，

前10幾次都沒事，format到字串一定大小的時程式會掛掉。