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Thread: Draw Line

  1. #1
    Join Date
    Jan 2009

    Question Draw Line

    I want to draw a line.
    I use this code

    private void OnMouseDown(object Sender, MouseEventArgs Args)
                    StartPoint = Args.GetPosition(DrawingCanvas);
    private void OnMouseMove(object Sender, MouseEventArgs Args)
     if (Args.LeftButton == MouseButtonState.Pressed)
                        EndPoint = Args.GetPosition(DrawingCanvas);
                        DrawLine(StartPoint, EndPoint, DrawingCanvas);
    private void DrawLine(Point From, Point To, Canvas TargetCanvas)
                CurrentLine = new Line();
                CurrentLine.StrokeEndLineCap = PenLineCap.Round;
                CurrentLine.StrokeStartLineCap = PenLineCap.Round;
                CurrentLine.Stroke = Brushes.Red;
                CurrentLine.StrokeThickness = 2.0;
                CurrentLine.X1 = From.X;
                CurrentLine.Y1 = From.Y;
                CurrentLine.X2 = To.X;
                CurrentLine.Y2 = To.Y;
                Canvas.SetLeft(TargetCanvas, From.X);
                Canvas.SetTop(TargetCanvas, From.Y);
    But the previous line is visible.
    How can I avoid that??

    Thanks & Regards

    Prajeesh Prabhakar
    Last edited by gstercken; April 20th, 2009 at 06:05 AM. Reason: Added code tags

  2. #2
    Join Date
    Sep 2002
    14 39'19.65"N / 121 1'44.34"E

    Re: Draw Line

    Quote Originally Posted by Prajeesh07 View Post
    But the previous line is visible.
    How can I avoid that??
    Well, this is sort of obvious, since it's exactly what your code does: It creates a new Line object on every MouseMove event. I guess what you intended is to create the new line in your MouseDown handler, and change only its end point when the mouse is moved?

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