关于图片读取的问题!

一段代码,读写BMP JPEG
void myfun::Write_Picture(String &sql,String &ColName_Picture,TImage *img)
{
//写
// 记住一定要在post前delete TADOBlobStream对象。
TADOQuery *qry1 = new TADOQuery(NULL);
qry1- >Connection = con;
qry1- >Close() ;
qry1- >SQL- >Clear() ;
qry1- >SQL- >Text = sql ;
qry1- >Open() ;
qry1- >Close() ;
qry1- >Open() ;
qry1- >Edit();
TBlobField * pField=(TBlobField *)qry1- >FieldByName(ColName_Picture);
TADOBlobStream * pmem=new TADOBlobStream (pField,bmWrite);
pmem- >Seek(0,soFromBeginning);
Graphics::TBitmap * pBitmap=new Graphics::TBitmap();
pBitmap- >Assign(img- >Picture- >Graphic);
pBitmap- >SaveToStream(pmem);
delete pBitmap;
delete pmem;
qry1- >Post();
delete qry1;
}
void myfun::Read_Picture(String &sql,String &ColName_Picture,TImage *img)
{
//读
TADOQuery *qry = new TADOQuery(NULL);
qry- >Connection = con;
qry- >Close() ;
qry- >SQL- >Clear() ;
qry- >SQL- >Text = sql ;
qry- >Open() ;
TBlobField * pField=(TBlobField *)qry- >FieldByName(ColName_Picture);
TADOBlobStream* pmem=new TADOBlobStream(pField,bmRead);
pmem- >Seek(0,soFromBeginning);
Graphics::TBitmap * pBitmap=new Graphics::TBitmap();
pBitmap- >LoadFromStream(pmem);
img- >Picture- >Bitmap- >Assign(pBitmap);
delete pBitmap;
delete pmem;
delete qry;
}