提示"....EDBEngineError Invalid Length",不知如何改之!

procedure TForm1.BtnSavePictureClick(Sender: TObject);
var
MemoryStream:TMemoryStream;
begin
MemoryStream:=TMemoryStream.Create;
image1.Picture.Bitmap.SaveToStream(MemoryStream);
MemoryStream.position:=0;
table1.open;
table1.insert;
TBlobField(table1.FieldByName('picture')).loadfromstream(MemoryStream);
table1.post;
end;
提示"....EDBEngineError Invalid Length",不知如何改之!