如何在Image显示图片的指定区域?

Question

图片比Timage控件大,装载时缺省是显示左上角,怎样才能显示指定区域?多谢

Answer 1

用Canvas.CopyRect将指定区域画上去

Answer 2

procedure TForm1.Button1Click(Sender: TObject);
var
  Bmp1, Bmp2: TBitmap;
  Ra, Rb : TRect;
begin
  Ra := Rect(30,30,Self.Image1.Width+30,Self.Image1.Height+30);
  Rb := Rect(0,0,Self.Image1.Width,Self.Image1.Height);
  Bmp1 := TBitmap.Create;
  Bmp2 := TBitmap.Create;
  Bmp2.Height := Image1.Height;
  Bmp2.Width  := Image1.Width;
  Bmp1.LoadFromFile('c:\a001.bmp');
  Bmp2.Canvas.CopyRect(Rb, Bmp1.Canvas, Ra);
  Image1.Picture.Bitmap.Assign(Bmp2);
  Bmp1.Free;
  Bmp2.Free;
end;

Answer 3

用copyrect可放在任何位置:
var
  Bitmap: TBitmap;
  MyRect, MyOther: TRect;
begin  MyRect := Rect(0,0,100,100);  MyOther := Rect(20,20,100, 201);
  Bitmap := TBitmap.Create;
  Bitmap.LoadFromFile('c:\windows\tartan.bmp');
  Image1.Canvas.CopyRect(MyOther,Bitmap.Canvas,MyRect);
  Bitmap.Free;
end;