[DrawLines] How to delete one line ?

[bertrod]

The question is the the subject : when I draw many lines with the drawlines tool, is it possible to delete juste one line ?

[Narcís]

Hi bertrod,

Yes, you could use something like the code below. This snippet removes the first drawn line.

Code: Select all

procedure TForm1.Button1Click(Sender: TObject);
begin
  ChartTool1.Lines[0].Destroy;
  Chart1.Refresh;
end;

[bertrod]

Thanks.

But now how to know on which line the user has clicked ? (I would like to enable a right-click on a line to delete it).

I see that the TDrawLine has a property ID and Index, do you think I can use one of them to identify a line ?

[Narcís]

Hi bertrod,

Yes, you can use something like:

Code: Select all

procedure TForm1.Chart1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
   if ((ChartTool1.Clicked(X,Y) <> nil) and not ChartTool1.EnableDraw) then
  begin
    ChartTool1.Clicked(X,Y).Destroy;
    Chart1.Refresh;
  end;
end;

[bertrod]

Great, thanks for your help