Today, I encountered a problem. After adding a new module, there is a problem when compiling the link under the VC. It took a long time, and finally found because the new module compiled and the existing module is different. It is C / C -> Code Generation-> Use Run-Time Library, this place must be consistent. Especially when introducing a third party library, confirm that the standard C library used by the third party library and the consistent you are using. Vc Use the Multithreaded DLL for the GUI program, and use Single Thread for the console program to note this. There is no such problem under Linux. Microsoft's standard library is too complicated, check the document, this is still clear about http://support.microsoft.com/default.aspx?scid=kb;n-us;q154419, but still not understanding, Why can't Microsoft's multi-thread library and single-line library can't make one?