GDI : How to delete a line on right click

Question

I have a homework its aplication for drawing lines on the form. I know how to draw them but I also have to delete them on right click. For example I click on the form with left click drag a line on release paint the line but if I press right click on it line will be removed. Does anyone have a any clue how to delete lines ??? Please help I have 5 days left :(

Jason Akkerman · Answer

public partial class Form1 : Form { Boolean drag; Point start; Point end; public Form1() { InitializeComponent(); } protected override void OnMouseDown(MouseEventArgs e) { if (e.Button == MouseButtons.Left) { drag = true; start.X = e.X; start.Y = e.Y; } else { drag = false; Graphics g = Graphics.FromHwnd(this.Handle); g.Clear(this.BackColor); } base.OnMouseDown(e); } protected override void OnMouseUp(MouseEventArgs e) { if (drag) { end.X = e.X; end.Y = e.Y; Graphics g = Graphics.FromHwnd(this.Handle); g.DrawLine(new Pen(Color.Black 2) start end); } base.OnMouseUp(e); } } That is a simple answer. If right clicking the form is just suppose to erase the last line drawn then you need to keep track of all the lines that have been drawn. I suggest a generic collection (or better yet a System.Collections.Stack) of a custom structure that contains two System.Drawing.Points. Capture the right click and remove the last line from the collection. Call the Invalidate() method of your form to force a redraw. Overload the OnPaint() method to draw each line in your collection.

Santhosh N · Answer

you could actually implement eraser for this and draw lines seperately.. you can check here for a sample on how to do this http://support.microsoft.com/kb/314945

Mahesh Chand · Answer

You actually don't delete a line. You're going to redraw all graphics objects again and this time you are not going redraw the line you want to delete.