ctypes使用HRESULT(python)

时间:2016-08-18 13:03:00

标签: python c++ dll ctypes

我正在编写一个使用python脚本调用的DLL,如下所示:

 //sample.h
 #include<stdio.h>
 typedef struct _data
{
 char * name;
}data,*xdata;
__declspec(dllexport) void getinfo(data xdata,HRESULT *error);


//sample.c
#include<stdio.h>
#include"sample.h"
void get(data xdata,HRESULT *error)
{ 
  //something is being done here
}

现在,用于调用上述函数的python脚本如下所示:

//sample.py
import ctypes 
import sys
from ctypes import *
mydll=CDLL('sample.dll')
class data(Structure):
    _fields_ = [('name',c_char_p)]

def get():
    xdata=data()
    error=HRESULT()
    mydll=CDLL('sample.dll')
    mydll.get.argtypes=[POINTER(data),POINTER(HRESULT)]
    mydll.get.restype = None
    mydll.get(xdata,error)
    return xdata.value,error.value

xdata=get()
error=get()
print "information=",xdata.value
print "error=", error.value

但是我在运行python脚本后得到的错误是:

Debug Assertion Failed!
Program:C:\Python27\pythonw.exe
File:minkernel\crts\ucrt\src\appcrt\stdio\fgets.cpp
Expression:stream.valid()

有人可以帮我解决问题吗?我写过的python脚本是不是写它的正确方法?

1 个答案:

答案 0 :(得分:0)

根据我的评论,我怀疑fgets()的错误在代码中未显示,但是在Python和C代码中也存在问题。这是我使用的DLL源,确保传递指向数据结构的指针:

typedef long HRESULT;

typedef struct _data {
    char * name;
} data;

// Make sure to pass a pointer to data.
__declspec(dllexport) void getinfo(data* pdata, HRESULT *error)
{
    pdata->name = "Mark";
    *error = 0;
}

以下是更正后的Python代码:

from ctypes import *

class data(Structure):
    _fields_ = [('name',c_char_p)]

def get():
    xdata=data()
    error=HRESULT()
    mydll=CDLL('sample.dll')
    mydll.getinfo.argtypes=[POINTER(data),POINTER(HRESULT)]
    mydll.getinfo.restype = None
    mydll.getinfo(xdata,error)
    return xdata,error

# Correction in next two lines
xdata,error = get()
print "information =",xdata.name
print "error =", error.value

输出:

information = Mark
error = 0