COM调用出错!!

[love_mfc]

void CENCControlDlg::OnButton1()
{
// TODO: Add your control notification handler code here

//Declare variables.
// Declare variables.

HRESULT hr;
IWMEncoder* pEncoder;
IWMEncStatistics* pStats;
IDispatch* pDispIndex;
IWMEncIndexerStats* pIndexStats;
long lFileCount, lPercent;
CComBSTR bstrFileName;

// Initialize the COM library and retrieve a pointer
// to an IWMEncoder interface.

hr = CoInitialize(NULL);
CoCreateInstance(CLSID_WMEncoder,
NULL,
CLSCTX_INPROC_SERVER,
IID_IWMEncoder,
(void**) &pEncoder);

// Retrieve a pointer to an IWMEncAttributes interface.

hr = pEncoder->get_Statistics(&pStats);

// Retrieve an IDispatch pointer to IWMEncIndexerStats interface.

hr = pStats->get_IndexerStats(&pDispIndex);

// Call QueryInterface() to retrieve a pointer to the
// IWMEncIndexerStats interface.

hr = pDispIndex->QueryInterface(IID_IWMEncIndexerStats,
(void**) &pIndexStats);//这时出错了内存错误!

// Retrieve information about the indexing process.

hr = pIndexStats->get_FileCount(&lFileCount);
hr = pIndexStats->get_FileName(0, &bstrFileName);
hr = pIndexStats->get_PercentComplete(&lPercent);

}
请问我应如何修改,它是SDK上照搬下来的都有内存访问出错问题, 是不是MICROSOFT bug??
UP有分!!

[love_mfc]

没有人懂COM调用吗|？

[Wargod2002]

你都没有加任何判断
CoCreateInstance(CLSID_WMEncoder,
NULL,
CLSCTX_INPROC_SERVER,
IID_IWMEncoder,
(void**) &pEncoder);
这里成功了吗？看看返回值是什么

[nscboy]

初始化COM库：
if (!AfxOleInit()) return FALSE;
将上面一句加在
BOOL CXXXXApp::InitInstance()函数中

[TIMDONG]

初始化COM库
::CoInitialize(NULL);