使用ctype导入dll函数

Question

我需要做一个VB6程序到python的移植。此程序，使用DLL与Bentel Kyo防盗控制单元进行通信。在VB6中，我以这种方式声明函数：

Public Declare Function PanelConnection Lib "C:\SupervisioneCasa\BisKyoUnit.dll" (ByVal Comando As Long, ByVal Porta As Byte, tentativi, ByRef pin As Byte, ByVal LenPin As Byte, ByRef presult As Byte) As Byte

并以这种方式调用函数：

ExitCode = PanelConnection(&H302, 1, 1, 0, 0, Buffer(0))

我尝试这样翻译python中的VB6代码：

import ctypes

hllDll = ctypes.WinDLL ("c:\\Appoggio\\BisKyoUnit.dll")

array_type = ctypes.c_byte * 255
Buffer = array_type()

hllApiProto = ctypes.WINFUNCTYPE (
    ctypes.c_byte,      # Return type.
    ctypes.c_long,   # Parameters 1 ...
    ctypes.c_byte,
    ctypes.c_int,
    ctypes.c_byte,
    ctypes.c_byte,
    ctypes.c_byte)   # ... thru 6.
hllApiParams = (1, "p1", 0), (1, "p2", 0), (1, "p3",0), (1, "p4",0), (1, "p5",0), (1, "p6",0),

hllApi = hllApiProto (("PanelConnection", hllDll), hllApiParams)

p1 = ctypes.c_long (302)
p2 = ctypes.c_byte (1)
p3 = ctypes.c_int (1)
p4 = ctypes.c_byte (0)
p5 = ctypes.c_byte (0)
p6 = ctypes.c_byte (Buffer)
hllApi (p1, p2, p3, p4, p5, p6)

但是当我尝试运行py时，我得到了这个错误：

Traceback (most recent call last):
  File "y:\Downloads\Python\Bentel.py", line 28, in <module>
    p6 = ctypes.c_byte (Buffer)
TypeError: an integer is required

我哪里错了？有人能帮我吗？谢谢。

尤里

Answer 1

我试着用这种方式重写函数：

import ctypes

dll = ctypes.windll.LoadLibrary("c:\\Appoggio\\BisKyoUnit.dll")

py_swe_calc_ut = dll.PanelConnection
py_swe_calc_ut.argtypes = [ctypes.c_long, ctypes.c_byte, ctypes.c_int, ctypes.c_byte, ctypes.c_byte, ctypes.POINTER(ctypes.c_byte*255)]
py_swe_calc_ut.restype = None

returnarray = (ctypes.c_byte * 255)()

ExitCode = py_swe_calc_ut(302, 1, 1, 0, 0, returnarray)

这样，就不会返回错误。但在实践中，调用并不起作用。在returnarray中不返回任何内容。有什么帮助吗？谢谢。