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我在 Visual Studio 2008 中下载并打开的示例项目中有以下代码行

_bstr_t bstrConnect = "PATH to MDB file";

int _tmain(int argc, _TCHAR* argv[]){
HRESULT hr = CoInitialize(NULL);
if (FAILED(hr))
{
    cout<<DAM<<": Failed to CoInitialize() COM."<<endl;
    return hr;
}

DAO::_DBEngine* pEngine = NULL;

hr = CoCreateInstance(
    __uuidof(DAO::DBEngine),
    NULL,
    CLSCTX_ALL,
    IID_IDispatch,
    (LPVOID*)&pEngine);
if (SUCCEEDED(hr) && pEngine)
{
    try
    {
        DAO::DatabasePtr pDbPtr = NULL;
        pDbPtr = pEngine->OpenDatabase(bstrConnect);

此代码有效。然后我将一些非常相似的代码放入 Visual Studio 2012 项目中

_bstr_t bstrConnect = "PATH to MDB file";

int _tmain(int argc, _TCHAR* argv[]) {
HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
if (FAILED(hr))
{
    cout<<"Failed to CoInitialize() COM."<<endl;
    cout << _com_error(hr).ErrorMessage() << endl;
    return hr;
}

DAO::_DBEngine* pEngine = NULL;

hr = CoCreateInstance(
    __uuidof(DAO::DBEngine),
    NULL,
    CLSCTX_ALL,
    IID_IDispatch,
    (LPVOID*)&pEngine);

if (SUCCEEDED(hr) && pEngine)
{
    try
    {
        DAO::DatabasePtr pDbPtr = NULL;
        pDbPtr = pEngine->OpenDatabase(bstrConnect);

在 2012 版本中，当我调用 pEngine->OpenDatabase 时，我得到一个 System.AccessViolationException。我需要在 2012 代码中更改什么吗？我最初在 2012 版本中有 CoInitialize，但它一直返回错误，直到我切换到 CoInitializeEx。

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