DLL在ctypes的Python 2.7中的使用

Question

I have a problem about using DLL file. The code I used is below. In handbook of DLL it writes the signiture of function. I'm using Python 2.7

from ctypes import *
mtrs= windll.LoadLibrary("mtrs.dll")
mtrs.sw_Open("SystemWorks", 0, c_ulong( 0x100 | 0x10000), None, None)
0

In handbook of DLL it writes the signature of function.

DLLINOUT BOOL WINAPI sw_Open(LPCSTR DeviceName, ULONG DeviceNumber, ULONG OpenFlags, void * Arg1, void * Arg2 );

Function returns false if device is not opened.

Is there any error in parameters?

Answer 1

如果使用的是Python 3x，则应使用b"SystemWorks"因为第一个参数的类型为LPCSTR 。

Answer 2

#!/usr/bin/env python3
from ctypes import *
mtrs= windll.LoadLibrary("mtrs.dll")
mtrs.sw_Open.argtypes = [c_char_p, c_ulong, c_ulong, c_void_p, c_void_p]
mtrs.sw_Open.restype = c_bool
mtrs.sw_Open(b"SystemWorks", c_ulong(0), c_ulong( 0x100 | 0x10000), None, None)