有关ADO实现存取Oracle数据库中的bitmap图像的问题

[diabloqin]

怎样用ADO实现向Oracle数据库存取bitmap图像？


最好有源码！谢谢了

[small_wei]

这个access和sql server的有关的读写数据库中的bitmap图像的问题.
不知oracle能不能用.
void CADOBlobDlg::ReadData()
{
//DestroyPhoto(); ///清除原图像
if(m_pRecordset->adoEOF||m_pRecordset->BOF)
{
m_UserName.Empty();
m_Old.Empty();
UpdateData(FALSE);
return;
}
long lDataSize = m_pRecordset->GetFields()->GetItem("photo")->ActualSize;
if(lDataSize > 0)
{
_variant_t varBLOB;
varBLOB = m_pRecordset->GetFields()->GetItem("photo")->GetChunk(lDataSize);
if(varBLOB.vt == (VT_ARRAY | VT_UI1))
{
if(m_pBMPBuffer = new char[lDataSize+1]) ///重新分配必要的存储空间
{
char *pBuf = NULL;
SafeArrayAccessData(varBLOB.parray,(void **)&pBuf);
memcpy(m_pBMPBuffer,pBuf,lDataSize); ///复制数据到缓冲区m_pBMPBuffer
SafeArrayUnaccessData (varBLOB.parray);
m_nFileLen = lDataSize;
m_hPhotoBitmap = BufferToHBITMAP(); ///生成BITMAP对象
}
}
}
m_UserName = m_pRecordset->GetCollect("username").bstrVal;
m_Old.Format("%d",m_pRecordset->GetCollect("old").lVal);
m_editUserName.EnableWindow();
m_editOld.EnableWindow();
m_buttonSelectPhoto.EnableWindow();
m_buttonDeleteUser.EnableWindow();
UpdateData(FALSE);
}

///////////将内存中的BMP文件内容转换到HBITMAP///////
HBITMAP CADOBlobDlg::BufferToHBITMAP()
{
HBITMAP hBmp;
LPSTR hDIB,lpBuffer = m_pBMPBuffer;
LPVOID lpDIBBits;
BITMAPFILEHEADER bmfHeader;
DWORD bmfHeaderLen;

bmfHeaderLen = sizeof(bmfHeader);
strncpy((LPSTR)&bmfHeader,(LPSTR)lpBuffer,bmfHeaderLen);
if (bmfHeader.bfType != ((WORD) ('M' << 8) | 'B')) return NULL;
hDIB = lpBuffer + bmfHeaderLen;
BITMAPINFOHEADER &bmiHeader = *(LPBITMAPINFOHEADER)hDIB ;
BITMAPINFO &bmInfo = *(LPBITMAPINFO)hDIB ;
int nColors = bmiHeader.biClrUsed ? bmiHeader.biClrUsed : 1 << bmiHeader.biBitCount;
if( bmInfo.bmiHeader.biBitCount > 8 )
lpDIBBits = (LPVOID)((LPDWORD)(bmInfo.bmiColors + bmInfo.bmiHeader.biClrUsed) +
((bmInfo.bmiHeader.biCompression == BI_BITFIELDS) ? 3 : 0));
else
lpDIBBits = (LPVOID)(bmInfo.bmiColors + nColors);
CClientDC dc(this);
hBmp = CreateDIBitmap(dc.m_hDC,&bmiHeader,CBM_INIT,lpDIBBits,&bmInfo,DIB_RGB_COLORS);
return hBmp;
}

[diabloqin]

.........
lpDIBBits = (LPVOID)(bmInfo.bmiColors + nColors);
CClientDC dc(this);
hBmp = CreateDIBitmap(dc.m_hDC,&bmiHeader,CBM_INIT,lpDIBBits,&bmInfo,DIB_RGB_COLORS);
return hBmp;


图片不能转换，返回值为0x00000000

help

[small_wei]

我这里刚运行过，没有问题，是不是原来写前去的数据有问题？

[rengm]

UP

[Virtuoso]

1. VC把一个文件存入数据库

CFile imagefile;
if(0 == imagefile.Open("d:\\user\\bmp.bmp",CFile::modeRead))
return;
_RecordsetPtr pRs = NULL;
_ConnectionPtr pConnection = NULL;
_variant_t varChunk;
HRESULT hr;
BYTE* pbuf;
long nLength = imagefile.GetLength();
pbuf = new BYTE[nLength+2];
if(pbuf == NULL)
return; //allocate memory error;
imagefile.Read(pbuf,nLength); //read the file into memory

BYTE *pBufEx;
pBufEx = pbuf;
//build a SAFFERRAY
SAFEARRAY* psa;
SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = nLength;
psa = SafeArrayCreate(VT_UI1, 1, rgsabound);

for (long i = 0; i < nLength; i++)
SafeArrayPutElement (psa, &i, pBufEx++);
VARIANT varBLOB;
varBLOB.vt = VT_ARRAY | VT_UI1;
varBLOB.parray = psa;

_bstr_t strCnn("Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=CUSTOM;Data Source=SERVER");
try
{
//Open a connection
pConnection.CreateInstance(__uuidof(Connection));
hr = pConnection->Open(strCnn,"","",NULL); //Connect a DataBase
pRs.CreateInstance(__uuidof(Recordset));
pRs->Open("CustomInfo",_variant_t((IDispatch *) pConnection,true),adOpenKeyset,adLockOptimistic,adCmdTable); //Open a Table

// pRs->AddNew();
pRs->Fields->GetItem("Image")->AppendChunk(varBLOB);
pRs->Update();
pRs->Close();
pConnection->Close();
}
catch(_com_error &e)
{
// Notify the user of errors if any.
_bstr_t bstrSource(e.Source());
_bstr_t bstrDescription(e.Description());
CString sError;
sError.Format("Source : %s \n Description : %s\n",(LPCSTR)bstrSource,(LPCSTR)bstrDescription);
AfxMessageBox(sError);
}

[diabloqin]

自己up