●●●求在TImage中移动Rectangle的示例●●●

Question

就是在Timage中画了个矩形，然后移动它，我无法擦除移动时的阴影，而且在移动时，鼠标动一下，图像移动比例很大，而不是1:1的距离。分不够另外给。谢谢

Answer 1

用Xor来擦除。var
    X:integer;procedure TForm1.Timer1Timer(Sender: TObject);
begin
    Image1.Canvas.Rectangle(X,100,X+100,200);
    inc(X,10);
    Image1.Canvas.Rectangle(X,100,X+100,200);
end;procedure TForm1.FormActivate(Sender: TObject);
begin
    Image1.Canvas.Pen.Color:=clRed;
    Image1.Canvas.Pen.Mode:=pmXor;
    Image1.Canvas.Brush.Style:=bsClear ;
    Image1.Canvas.Rectangle(X,100,X+100,200);
end;

Answer 2

有没有在MouseMove中进行处理的

Answer 3

跟随Mouse 的位置吗？
想要Rectangle和鼠标的位置有什么关系呢？

Answer 4

就是鼠标移动时，Rectangle也跟着移动
我用你的代码试了下，还是有点问题，你可以试下
procedure TfrmMain.FormActivate(Sender: TObject);
begin
    imgTime.Canvas.Pen.Color:=clRed;
    imgTime.Canvas.Pen.Mode:=pmXor;
    imgTime.Canvas.Brush.Color := clRed;
    //imgTime.Canvas.Brush.Style:=bsClear;
    imgTime.Canvas.Rectangle(0,100,100,200);
    OldPoint := Point(0,100);
end;procedure TfrmMain.imgTimeMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
    if IsDraw then
    begin
    imgTime.Canvas.Pen.Color:=clRed;
    imgTime.Canvas.Pen.Mode:=pmXor;
    imgTime.Canvas.Brush.Color := clRed;
    imgTime.Canvas.Rectangle(OldPoint.X,100,OldPoint.X+100,200);
    OldPoint := Point(X,Y);
    imgTime.Canvas.Rectangle(OldPoint.X,100,OldPoint.X+100,200);
    end;
end;procedure TfrmMain.imgTimeMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
    imgTime.Canvas.Brush.Color := clWhite;
    imgTime.Canvas.Pen.Color:=clWhite;
    imgTime.Canvas.Pen.Mode:=pmCOPY;
    imgTime.Canvas.Rectangle(0,100,100,200);
    OldPoint := Point(0,100);
    IsDraw := True;
end;procedure TfrmMain.imgTimeMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
    IsDraw := False;
end;

Answer 5

是你的逻辑有一点点乱，把你的代码改一改，看看是否满足你的要求：procedure TForm1.imgTimeMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
    imgTime.Canvas.Pen.Color:=clRed;
    imgTime.Canvas.Pen.Mode:=pmXor;
    imgTime.Canvas.Brush.Color := clRed;
    imgTime.Canvas.Rectangle(OldPoint.X,OldPoint.Y,OldPoint.X+100,OldPoint.Y+100);
    OldPoint := Point(X,Y);
    imgTime.Canvas.Rectangle(OldPoint.X,OldPoint.Y,OldPoint.X+100,OldPoint.Y+100);
    IsDraw := True;
end;procedure TForm1.imgTimeMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
    IsDraw := False;
end;procedure TForm1.imgTimeMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
    if IsDraw then
    begin
        imgTime.Canvas.Rectangle(OldPoint.X,OldPoint.Y,OldPoint.X+100,OldPoint.Y+100);
        OldPoint := Point(X,Y);
        imgTime.Canvas.Rectangle(OldPoint.X,OldPoint.Y,OldPoint.X+100,OldPoint.Y+100);
    end;
end;procedure TForm1.FormActivate(Sender: TObject);
begin
    imgTime.Canvas.Pen.Color:=clRed;
    imgTime.Canvas.Pen.Mode:=pmXor;
    imgTime.Canvas.Brush.Color := clRed;
    OldPoint := Point(0,100);
    imgTime.Canvas.Rectangle(OldPoint.X,OldPoint.Y,OldPoint.X+100,OldPoint.Y+100);
end;

Answer 6

可以做一个缓冲，就是背景图作一个缓冲，每次刷到Image上去的时候就用背景图和方框合成一下。鼠标运动可以强制Image刷新，合成刷图的程序放在image的onpaint事件立面处理。