Einen Bilderausschnitt aus TImage

[Luckie]

Delphi-Quellcode:

type
  TForm1 = class(TForm)
    Image2: TImage;
    Button1: TButton;
    Image1: TImage;
    procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure Image1MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
    StartPoint: TPoint;
    EndPoint: TPoint;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  StartPoint.X := X;
  StartPoint.Y := Y;
  Image1.Canvas.Ellipse(X, Y, X + 5, Y + 5);
end;

procedure TForm1.Image1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  EndPoint.X := X;
  EndPoint.Y := Y;
  Image1.Canvas.Ellipse(X, Y, X + 5, Y + 5);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  SrcRect, DestRect: TRect;
begin
  Image2.Picture := nil;
  SrcRect.Left := StartPoint.X;
  SrcRect.Top := StartPoint.Y;
  SrcRect.Right := EndPoint.X;
  SrcRect.Bottom := EndPoint.Y;
  DestRect := Rect(0, 0, EndPoint.X - StartPoint.X, EndPoint.Y -
    StartPoint.Y);
  Image2.Canvas.CopyRect(DestRect, Image1.Canvas, SrcRect);
end;