Python ctypes and not enough arguments (4 bytes missing)

Question

The function i\'m trying to call is:

void FormatError (HRESULT hrError,PCHAR pszText);

from a custom dll using windll.

c_p          


        

Answer 1

At the very least, you'll get more descriptive errors if you properly set up the argtypes and the restype.

Try doing it this way:

windll.thedll.FormatError.argtypes = [ctypes.HRESULT, ctypes.c_char_p]
windll.thedll.FormatError.restype  = None

There's also a very good chance you are using the wrong calling convention -- check out the Calling Functions section and the Loading Libraries section for details on how to use a different calling convention.

Answer 2

Actually I think you want to use FormatError as provided by ctypes

http://docs.python.org/library/ctypes.html#ctypes.FormatError

ctypes.FormatError([code])

Windows only: Returns a textual description of the error code. If no error code is specified, the last error code is used by calling the Windows api function GetLastError.

Answer 3

Have you tried to use the ctypes.HRESULT?