数据库ADO方式读取图片

void Caccess_test_1Dlg::OnBnClickedButton3()//将偏振图像存入数据库
{
    // TODO:  在此添加控件通知处理程序代码
    if (!PathFileExists(_T(filename)))
    {
        AfxMessageBox(_T("数据库不存在！\r请创建数据库！"));
        return;
    }
    try
    {
        m_pConnection.CreateInstance(__uuidof(Connection));
        m_pRecordset.CreateInstance("ADODB.Recordset");
        m_pConnection->Open(StrCmd, "", "", adModeUnknown);
        m_pRecordset->Open("SELECT * FROM p ", _variant_t(m_pConnection, true), adOpenStatic, adLockOptimistic, adCmdText);
    }
    catch (_com_error e)
    {
        CString errormessage;
        errormessage.Format(_T("连接数据库失败！\r错误信息:%s"), e.ErrorMessage());
        AfxMessageBox(errormessage);
        return;
    }


    
    CFile f;
    CString  FilePathName;
    CFileException e;

    CFileDialog dlg(TRUE,NULL, NULL, 0, L"jpg Files (*.jpg)|*.jpg||", this);///TRUE为OPEN对话框，FALSE为SAVE AS对话框
    if (dlg.DoModal() == IDOK)
    {
        FilePathName = dlg.GetPathName();

        if (m_Pic.m_IPicture != NULL) m_Pic.FreePictureData(); // Important - Avoid Leaks...

        if (f.Open(FilePathName, CFile::modeRead | CFile::typeBinary, &e)) //打开了一个jpg文件
        {

            int nSize = f.GetLength();          //先得到jpg文件长度
            BYTE * pBuffer = new BYTE[nSize];  //按文件的大小在堆上申请一块内存

            if (f.Read(pBuffer, nSize) > 0)    //把jpg文件读到pBuffer(堆上申请一块内存)
            {   // +----------------------------------------------
                BYTE *pBuf = pBuffer;     ///下面这一大段是把pBuffer里的jpg数据放到库中
                VARIANT            varBLOB;
                SAFEARRAY        *psa;
                SAFEARRAYBOUND    rgsabound[1];
                //m_pRecordset.CreateInstance(__uuidof(Recordset));
                
                m_pRecordset->AddNew();
                if (pBuf)
                {
                    rgsabound[0].lLbound = 0;
                    rgsabound[0].cElements = nSize;
                    psa = SafeArrayCreate(VT_UI1, 1, rgsabound);
                    for (long i = 0; i < (long)nSize; i++)
                        SafeArrayPutElement(psa, &i, pBuf++);
                    varBLOB.vt = VT_ARRAY | VT_UI1;
                    varBLOB.parray = psa;
                    m_pRecordset->GetFields()->GetItem("偏振度图像")->AppendChunk(varBLOB);
                }
                m_pRecordset->Update();
                // +----------------------------------------------
                //(m_Pic.LoadPictureData(pBuffer, nSize));//接作调用函数读pBuffer的jpg数据准备显示
                delete[] pBuffer;     //删掉堆上申请的那一块内存
                pBuf = 0;                //以防二次乱用
            }
            f.Close();
        }

    //    CClientDC dc(this);
        //m_Pic.UpdateSizeOnDC(&dc); // Get Picture Dimentions In Pixels
        //m_Pic.Show(&dc, CRect(0, 50, m_Pic.m_Width, 50 + m_Pic.m_Height)); //显示出来看看

    }
    //Invalidate();
}

m_pRecordset.CreateInstance