msxml程序的最后一行出错

Question

我正在使用MSXML 4.0来解析我的xml.

该程序工作正常,但在程序终止之前,我得到以下异常

db2.exe中0x00417be5处的未处理异常:0xC0000005:访问冲突读取位置0x00b1c740.

at comip.hat _Release()method at linem_pInterface->Release();

这是我的代码

#include <iostream>
#include "stdafx.h"
#include "Database.h"
#include <sstream>
#include <objbase.h>
#import <msxml4.dll>

using namespace std;


void main(int argc, _TCHAR* argv[])
{
    ::CoInitialize(NULL);
    MSXML2::IXMLDOMDocumentPtr pXMLDom;
    HRESULT hr= pXMLDom.CreateInstance(__uuidof(MSXML2::DOMDocument40), NULL, CLSCTX_INPROC_SERVER); //Msxml2.DOMDocument.4.0 

    if (FAILED(hr)) 
    {
      printf("Failed to instantiate an XML DOM.\n");
      //return 0;
    }

    try
    {
        pXMLDom->async = VARIANT_FALSE;
        pXMLDom->validateOnParse = VARIANT_FALSE;
        pXMLDom->resolveExternals = VARIANT_FALSE;

        if(pXMLDom->load("users.xml") == VARIANT_TRUE)
        {
            printf("XML DOM loaded from users.xml:\n%s\n", (LPCSTR)pXMLDom->xml);
        }
        else
        {
            // Failed to load xml
            printf("Failed to load DOM from stocks.xml. %s\n",
                   (LPCSTR)pXMLDom->parseError->Getreason());
        }
        ::CoUninitialize();
    }
    catch(_com_error errorObject)
    {
        printf("Exception thrown, HRESULT: 0x%08x", errorObject.Error());
    }
    catch(...)
    {
        printf("Unknown error");
    }   
}

我不知道我的程序有什么问题.它只是在最后一行之前抛出一个异常.

有人能指出我正确的方向吗？

编辑:奇怪我::CoUninitialize();从我的程序中删除它,它工作正常.

::CoUninitialize();方法有什么问题？

谢谢,

Answer 1

您在调用后隐式使用COM CoUninitialize.这是在析构函数中完成的MSXML2::IXMLDOMDocumentPtr,它会调用函数IXMLDOMDocument::Release.

CoUninitialize 必须是有史以来最后一个COM函数.

进行这些更改,它将起作用.我已经确定CoUninitialize将在析构函数之后调用MSXML2::IXMLDOMDocumentPtr:

void XMLDomTest()
{
    MSXML2::IXMLDOMDocumentPtr pXMLDom;
    HRESULT hr= pXMLDom.CreateInstance(__uuidof(MSXML2::DOMDocument40), NULL, CLSCTX_INPROC_SERVER); //Msxml2.DOMDocument.4.0 

    if (FAILED(hr)) 
    {
      printf("Failed to instantiate an XML DOM.\n");
      return;
    }

    try
    {
        pXMLDom->async = VARIANT_FALSE;
        pXMLDom->validateOnParse = VARIANT_FALSE;
        pXMLDom->resolveExternals = VARIANT_FALSE;

        if(pXMLDom->load("users.xml") == VARIANT_TRUE)
        {
            printf("XML DOM loaded from users.xml:\n%s\n", (LPCSTR)pXMLDom->xml);
        }
        else
        {
            // Failed to load xml
            printf("Failed to load DOM from stocks.xml. %s\n",
                   (LPCSTR)pXMLDom->parseError->Getreason());
        }
    }
    catch(_com_error errorObject)
    {
        printf("Exception thrown, HRESULT: 0x%08x", errorObject.Error());
    }
    catch(...)
    {
        printf("Unknown error");
    }   
}

void main(int argc, _TCHAR* argv[])
{
    ::CoInitialize(NULL);
    XMLDomTest();
    ::CoUninitialize();
}