帮忙！！！！ (50分)

procedure TForm1.PaintBox1Paint(Sender: TObject);
var bmpTmp:Tbitmap;
begin

bmpTmp:=Tbitmap.Create;
bmpTmp.Canvas.Brush.Color:=clred;
bmpTmp.Canvas.FillRect(Rect(10,10,50,50));
PaintBox1.Canvas.CopyRect(Rect(10,10,50,50),bmptmp.Canvas,Rect(10,10,50,50));
PaintBox1.Canvas.Draw(10,10,bmptmp);
bmpTmp.Free;
end;
怎么什么也不显示呀？

你bmp中有图画吗？

PaintBox1是不是要刷新？

bmp没画好！
procedure TForm1.PaintBox1Paint(Sender: TObject);
var bmpTmp:Tbitmap;
R:TRect;
begin
R:= Rect(10,10,50,50);
bmpTmp:=TBitmap.Create;
with bmpTmp do
begin
Height := 60;
Width := 60;
with Canvas do
begin
Brush.Color:=clred;//clWhite;
FillRect(R);
end;
end;
PaintBox1.Canvas.CopyRect(R, bmpTmp.Canvas,R);
PaintBox1.Canvas.Draw(0,0,bmpTmp);
bmpTmp.Free;
end;
这样就OK了！

你bmpTmp缺少图画。是空的！
procedure TForm1.PaintBox1Paint(Sender: TObject);
var bmpTmp:Tbitmap;
begin

bmpTmp:=Tbitmap.Create;

bmpTmp.Canvas.Brush.Color:=clred;
bmpTmp.Canvas.FillRect(Rect(10,10,50,50));
PaintBox1.Canvas.Brush.Color := clRed;
PaintBox1.Canvas.FillRect(PaintBox1.Canvas.ClipRect);
PaintBox1.Canvas.Ellipse(0,0,100,100);
// PaintBox1.Canvas.CopyRect(Rect(10,10,50,50),bmptmp.Canvas,Rect(10,10,50,50));
// PaintBox1.Canvas.Draw(10,10,bmptmp);
bmpTmp.Free;

end;

多人接受答案了。