VC/VB 进行图像数据存储数据库心得

　2007-03-22 21:31:50　来源：WEB开发网　　　

核心提示：网上经常有人问如何把图像存入数据库中，原先我也是不得要领，VC/VB 进行图像数据存储数据库心得，经过多方指点和自己在开发过程中的摸索，终于解决这一问题，下面给出用VC，VB如何操作图像文件存取数据库的原码

网上经常有人问如何把图像存入数据库中，原先我也是不得要领。经过多方指点和自己在开发过程中的摸索，终于解决这一问题。下面给出用VC，VB如何操作图像文件存取数据库的原码，帮助一些还没有掌握方法的朋友（均用ADO连接数据库）。

一、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 
 Description : %s
",(LPCSTR)bstrSource,(LPCSTR)bstrDescription);
AfxMessageBox(sError);
}