Now  the Other man have a DLL (a.dll) that make in VC
so, I  use VC  write a  Static library  (a.lib) to  linke the DLL
a.lib have one Fun: 
extern "C" int Init(char*);
now , the codeblocks linker a.lib have the question:
mylib.cpp: undefined reference to `Init'
but, I look for the a.lib with the VS Cmd dumpbin /linkermember , it can look up Init Fun.
there the question ? 
It took me 3 days long........