但是在 Delphi for Win32 可以正常列印

procedure TForm1.Button1Click(Sender: TObject);
var
Abitmap: TBitmap;
begin

Abitmap:= TBitmap.Create;
try
Abitmap.Height:= Self.ClientHeight;
Abitmap.Width:= Self.ClientWidth;
Self.PaintTo(Abitmap.Canvas,0,0);

Image1.Picture.Assign(Abitmap);
finally
Abitmap.Free;
end;

end;

這段： Panel1 上的所有元件都不會被畫出來，為什麼？

Object reference not set to an instance of an object.

procedure TForm1.Button3Click(Sender: TObject);
var
Abitmap: TBitmap;
i: Integer;
begin

Abitmap:= TBitmap.Create;
try
Abitmap.Height:= Panel1.ClientHeight;
Abitmap.Width:= Panel1.ClientWidth;

for i:= 0 to Panel1.ControlCount-1 do
with TWinControl(Panel1.Controls[i]) do
if Visible then
PaintTo(Abitmap.Canvas, Left, Top);

Image1.Picture.Assign(Abitmap);
finally
Abitmap.Free;
end;

end;