COM 编写ＤＬＬ　回调函数

2008-11-17 03:36:51 151 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

简单实现基于C++的COM组件创建与DLL封装简单实现基于C++的COM组件创建与DLL封装，包括组件、COM、COM组件、DLL等基本概念与关系，使用C++进行COM组件创建与DLL封装调用等的简单实现。阅读详情

dll 代码:

test.h文件部分关键代码
IControlClientPtr s_CtrlClientPtr;
typedef int (*completecbfn)(int channum,char * filename,void *flag);

test.cpp文件部分关键代码
static completecbfn m_compfn;
CTestApp theApp;

构造函数中已经 compfn＝NULL;
#define NET_API extern "C"__declspec(dllexport)
NET_API int _stdcall record(void *handle, unsigned int channum, short time, char* filename, void* flag, completecbfn pcbfn)
{
m_compfn = pcbfn;
//test.dll调用下层另外一个dll文件
int rtn = theApp.s_CtrlClientPtr->record((long)handle, channum, time, filename);
return rtn;
}

STDMETHODIMP CTestApp::XEventSink::Invoke(DISPID dispid, REFIID, LCID, unsigned short wFlags
, DISPPARAMS* pDispParams, VARIANT* pvarResult, EXCEPINFO* pExcepInfo
, unsigned int* puArgError)
{
if (m_compfn!=NULL)
{
AfxMessageBox("Not NULL");
}else{
AfxMessageBox("NULL");
}

if(dispid == 2)
{
int channum = 0;//pDispParams->rgvarg[1].intVal;
CString temp = pDispParams->rgvarg[0].bstrVal;
char filename[256];
channum = atoi(temp.Mid(3,3));
wsprintf(filename,"%s",temp.Mid(13,255));

AfxMessageBox(filename);

int flag = 1;
int i1=0;
if (m_compfn!=NULL)
i1=m_compfn(channum,filename,&flag);//步骤A
}
return S_OK;
}
用户点击主界面录制按钮响应record事件,录制文件成功,但是当事件自动分发执行invoke中时,录制的dispid=2,所以执行if体,当运行到步骤A时,出现错误显示(Debug Assertion Failed!).想知道为什么这里回调机制会出现问题

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