剛接觸這個問題的時候在網上也是蒐羅了一大堆，大多數做下來沒有成功，原因未知，很可能是我的功底不夠吧，這裡記錄一下我成功的demo，希望能版主其他人。

首先就是使用vs2010建立一個dll庫（空專案）的工程，
新增原始檔（如：hello.cpp）

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define EXPORT_PKG_DLL
#include "hello.h"

PKG_API int GetStructInfo(struct StructInfo* pStruct)
{
    pStruct->
 
soh = 0x55;
    pStruct->id = 0x1234;

    pStruct->cmd = 0x56;
    pStruct->len = 0x9;
    strncpy(pStruct->data,'hello',5);
    pStruct->crc = 0x90f2;
    return TURE;
}

定義hello.h檔案：

#ifdef EXPORT_PKG_DLL  
#define PKG_API __declspec(dllexport)  
#else  
#define PKG_API __declspec(dllimport)  
 

#endif  

#define     PKG_SOH     0x55
#define     TURE        0
#define     FALSE       1

#define DATA_LEN    256

struct StructInfo
{
    int soh;
    int id;
    int cmd;
    int len;
    char data[DATA_LEN];
    int crc;
};

extern "C"  
{  
    PKG_API int GetStructInfo(const char *src,struct StructInfo* pStruct);  
}  
 

然後編譯生成*.dll檔案，（rg：pycall.dll）

接下來就是編寫py程式：

from ctypes import *

DEST_LEN = 270
DATA_LEN = 256
#define type
DESTARRAY270 = c_char * DEST_LEN;#int []
CHARARRAY256 = c_char * DATA_LEN;#char []
#define struct c_char_p: *  c_int :int

class StructPkg(Structure):
    _fields_ = [
        ("soh", c_int),
        ("id", c_int),
        ("cmd", c_int),
        ("len", c_int),
        ("data", CHARARRAY256),
        ("crc", c_int),
               ]


dll = cdll.LoadLibrary('pycall.dll');
GetStructInfo = dll.GetStructInfo;
#set the return type
GetStructInfo.restype = c_int;
#set the argtypes
GetStructInfo.argtypes = [c_char_p,POINTER(StructPkg)];

objectStruct = StructPkg()
#invoke api GetStructInfo
test = bytes([85,1,2,1,12])
teststr = 'get data cmd'
testcrc = bytes([0x71,0x79])
ll = test+teststr.encode('utf-8')+testcrc

retStr = GetStructInfo(ll,byref(objectStruct));
print(objectStruct)
# #check result
print ("soh: ", objectStruct.soh)
print ("id: ", objectStruct.id)
print ("cmd: ", objectStruct.cmd)
print ("len: ", objectStruct.len)
print ("data: ", objectStruct.data)
print ("crc: ", objectStruct.crc)
print (retStr);

結果如下:(程式很簡單這裡不做太多的說明)