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, , 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) > )    //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[];

                //m_pRecordset.CreateInstance(__uuidof(Recordset));

                m_pRecordset->AddNew();

                if (pBuf)

                {

                    rgsabound[].lLbound = ;

                    rgsabound[].cElements = nSize;

                    psa = SafeArrayCreate(VT_UI1, , rgsabound);

                    for (long i = ; 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 = ;                //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