function Control2Bitmap(Control_: TWinControl): TBitmap;
begin
  Result := TBitmap.Create;
  with Result do begin
    Height := Control_.Height;
    Width  := Control_.Width;
    Canvas.Handle := CreateDC(nil, nil, nil, nil);
    Canvas.Lock;
    Control_.PaintTo(Canvas.Handle, 0, 0);
    Canvas.Unlock;
    DeleteDC(Canvas.Handle);
  end;
end;

procedure TFormMain.tbtnGetPicGridClick(Sender: TObject);
var
  ThisBitmap: TBitmap;
begin
  ThisBitmap := Control2Bitmap(FlowPanel);
  CodeSite.Send('TFormMain.tbtnGetPicGridClick: ThisBitmap', ThisBitmap);
  ImageEnView1.Bitmap.Assign(ThisBitmap);
  ThisBitmap.ReleaseHandle;
  ThisBitmap.Free;
end;

ImageEnView1.IEBitmap.CopyFromTBitmap(ThisBitmap);