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/////////////////////读取记录集当前记录中数据,包括图像数据//////////////
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;
if (bmfHeader.bfType != (*(WORD*)"BM")) return NULL;//copy《Windows程序设计》上的做法。
hDIB = lpBuffer + bmfHeaderLen;
BITMAPINFOHEADER &bmiHeader = *(LPBITMAPINFOHEADER)hDIB ;
BITMAPINFO &bmInfo = *(LPBITMAPINFO)hDIB ;
lpDIBBits=(lpBuffer)+((BITMAPFILEHEADER *)lpBuffer)->bfOffBits;
CClientDC dc(this);
hBmp = CreateDIBitmap(dc.m_hDC,&bmiHeader,CBM_INIT,lpDIBBits,&bmInfo,DIB_RGB_COLORS);
return hBmp;
}