Re: Why ctypes always returns True?

Have you tried setting an explicit return value on the function object? Also, I would try & hard-code the return value to False so that you can be sure that the returning is the issue, not the passing.

And one last note: I *think* ctypes.cdll is wrong, it uses the wrong calling convention, that might lead to the passing of a wrong param. I'm no windows expert though, but make sure the library uses cdecl, not stdcall. Or use ctypes.windll

http://docs.python.org/2/library/ctypes.html#loading-dynamic-link-libraries

Diez


On Aug 15, 2013, at 1:26 PM, zhangxaochen wrote:

> My c code is:
>     extern "C" __declspec(dllexport) bool isTrue( bool b){ return b; }
> py code is:
>     lib=ctypes.cdll.LoadLibrary('xx.dll') #dll generated from the c code above
>     b=lib.isTrue(False) 
>     print c_bool(b).value
> 
> no matter i call lib.isTrue() with True or False, the output is always 'True'.....
> could someone explain?
> 
> 
> 
> 
> 
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