位图保存为流，报Abstract error
procedure TForm1.btnSaveAsClick(Sender: TObject);
var
aJpg: TJpegImage;
tsStream: TStream;
begin
aJpg := TJpegImage.Create;
tsStream := TStream.Create;
try
Image1.Picture.Bitmap.SaveToStream(tsStream);
aJpg.LoadFromStream(tsStream);
aJpg.SaveToFile( 'cc.jpg ');
finally
aJpg.Free;
tsStream.Free;
end;
end;


在“Image1.Picture.Bitmap.SaveToStream(tsStream);”时报错：Abstract error

[解决办法]
在 aJpg.LoadFromStream(mmStream); 之前加一名句:mmStream.Position := 0;