LIne and Arrows in windowsForm

This is easy enough. You need to handle the even System.Window.Forms.Control.Paint or override the virtual method System.Window.Forms.Control.OnPaint of some control (including Form). You will get an instance of System.Drawing.Graphics, passed to your handler method through event arguments parameter. Use it to draw on the control. To modify the image, change the data used for drawing and call System.Window.Forms.Control.Invalidate. To prevent flicker, use double buffering.

Please see my past answers for further detail:

capture the drawing on a panel[^],
What kind of playful method is Paint? (DataGridViewImageCell.Paint(...))[^],
How to speed up my vb.net application?[^],
Drawing Lines between mdi child forms[^],
Zoom image in C# .net mouse wheel[^].

I hope you got the idea.

—SA