VC++中ADO编程的问题，高手来接分！

[heavenb]

HRESULT hr;

hr=m_pConnection.CreateInstance("ADODB.Connection");///创建Connection对象
if(SUCCEEDED(hr))
{
hr = m_pConnection->Open("Provider=SQLOLEDB; Server=madcoder;"
"Database=NorthWind; uid=sa; pwd=98009207;","","",adModeUnknown);
if (!m_pConnection->State)
AfxMessageBox("hehe");
}
跟踪的时候发现，hr总是不能正确的初始化，总是个负值,怎么回事啊？

[BuZhang_AP97091]

try{
hr=m_pConnection.CreateInstance("ADODB.Connection");///创建Connection对象
if(SUCCEEDED(hr))
{
hr = m_pConnection->Open("Provider=SQLOLEDB; Server=madcoder;"
"Database=NorthWind; uid=sa; pwd=98009207;","","",adModeUnknown);
if (!m_pConnection->State)
AfxMessageBox("hehe");
}
}
catch(_com_error &e)
{
_bstr_t bstrSource(e.Source());
_bstr_t bs = _bstr_t(" Error: ") + _bstr_t(e.Error()) + _bstr_t(" Msg: ")
+ _bstr_t(e.ErrorMessage()) + _bstr_t(" Description: ")
+ _bstr_t(e.Description());

MessageBox(0,bs,bstrSource, MB_OK);
}
加上上面一段代码，查看异常，并有中文出错提示。
你还可以用
int nRet = GetLastError();
来看出错的地方在哪里。不过这个没有上面来得详细，建议用第一个。

[BombZhang]

hr = m_pConnection->Open("Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initial Catalog=NorthWind;Data Source=madcoder;Password=98009207","","",adModeUnknown);

[内存泄漏]

你写了初始化COM的语句没有？？

CoInitialize(NULL);

[bohut]

App类的InitInstance()函数里面添加：
CoInitialize(NULL);

[martingod]

同意楼上的，你是否CoInitialize(NULL);初始化了com？？

[laker_tmj]

CoInitialize(NULL);

[yuanl]

String strConnection = "driver={SQL Server};Server=192.168.0.100;DATABASE=jskj;UID=sa";//sql2000
try
{
hr = m_pConnTemp.CreateInstance("ADODB.Connection");//

if(SUCCEEDED(hr))
{
hr=m_pConnTemp->Open((_bstr_t)strConnection,"","",adModeUnknown);
}
}
catch(_com_error e)
{
CCommon common;
AfxMessageBox(common.DisplayAdoError(m_pConnTemp));
}
if (m_pConnTemp != NULL)
{
if (m_pConnTemp->State)
{
if (m_pConnection != NULL)
{
if (m_pConnection->State)
{
m_pConnection->Close ();
}
}
m_pConnection = m_pConnTemp;
}
}