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数据库的OLE字段写入长二进制文件
//‘***************************************************************************************
//‘函数:将数据库的OLE字段写入长二进制文件
//‘***************************************************************************************
//bool THsPart_clsPartCommonDB::PrintFieldToFile(TheFiled As ADODB.Field, ByVal strSaveName As String, _
// Optional IsAppend As Boolean)
bool THsPart_clsPartEntityDB::PrintFieldToFile(_RecordsetPtr &myRcdPtr,_variant_t index ,CString strSaveName /*ADODB.Fields TheFiled, CString strSaveName ,*Optional IsAppend As Boolean*/)
{
//Dim MyRc As Recordset;
VARIANT varBLOB;
CFile myfile;
bool bReturn = false;
try
{
//‘定义各种参数
const int conChunkSize = 16384;
int Chunks ;
byte *Chunk = NULL; //Chunk() As Byte,
//int FileNumber;
long FragMent ,lngTotalSize;
// 定义各种参数
myfile.Open(strSaveName,CFile::modeCreate|CFile::modeReadWrite|CFile::typeBinary);
/*FileNumber = FreeFile;
Open strSaveName For Binary Access Write As #FileNumber;*/
//将字段内的长二进制文件导出的文件
lngTotalSize = myRcdPtr->Fields->GetItem(index)->ActualSize; //lngTotalSize = TheFiled.ActualSize;
Chunks = lngTotalSize /conChunkSize;
FragMent = lngTotalSize % conChunkSize;
Chunk = (byte *)GlobalAlloc(GMEM_FIXED,FragMent); //ReDim Chunk(FragMent);
varBLOB= myRcdPtr->Fields->GetItem(index)->GetChunk(FragMent); //Chunk() = TheFiled.GetChunk(FragMent);
SafeArrayAccessData(varBLOB.parray,(void **)&Chunk);
LPSTR buffer = (LPSTR)GlobalLock((HGLOBAL)Chunk);
myfile.Write(buffer,FragMent);
GlobalUnlock((HGLOBAL)Chunk);
SafeArrayUnaccessData (varBLOB.parray);
int counter;
Chunk = (byte *)GlobalAlloc(GMEM_FIXED,conChunkSize);
for(counter=1;counter<= Chunks;counter++) //For counter = 1 To Chunks
{
//Chunk() = TheFiled.GetChunk(conChunkSize);
varBLOB= myRcdPtr->Fields->GetItem(index)->GetChunk(conChunkSize);
SafeArrayAccessData(varBLOB.parray,(void **)&Chunk);
buffer = (LPSTR)GlobalLock((HGLOBAL)Chunk);
myfile.Write(Chunk,FragMent);
SafeArrayUnaccessData (varBLOB.parray);
}
GlobalUnlock((HGLOBAL)Chunk);
Chunk = NULL;
buffer = NULL;
////////////////////////////////////////////////
////////////////////////////
//////////
//Close #FileNumber
myfile.Close();
bReturn = true;
return bReturn;
}
catch(...)
{
AfxMessageBox(_T("PrintFieldToFile wrong!"));
//Close #FileNumber;
myfile.Close();
}
return bReturn;
}
数据库的OLE字段写入长二进制文件
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