How to draw sketch lines with C# and GDI+

Question

Is it possible to draw lines and figures like shown below in GDI+ and c#?

May be there is some way to do that in easy way in c#?

Update: I mean that I need to imitate Hand-Drawing effect in GDI+ I would like to write something like:

graphics.DrawHandDrawnLine(Pens.Black, x1, y1, x2, y2);

and see something like this

Answer 1

I believe this will be hard to top in the 'more easy' department..:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing.Imaging;
using System.Drawing;
using System.Linq;

using System.Windows.Forms;

namespace Doodle
{
  public partial class Form1 : Form
  {
    public Form1()
    {
        InitializeComponent();
    }

    List<Point> curPoints = new List<Point>();
    List<List<Point>> allPoints = new List<List<Point>>();

    private void pnlPaint_MouseDown(object sender, MouseEventArgs e)
    {
        if (curPoints.Count > 1)
        {
            // begin fresh line
            curPoints.Clear();
            // startpoint
            curPoints.Add(e.Location);
        }
    }

    private void pnlPaint_MouseUp(object sender, MouseEventArgs e)
    {
        if (curPoints.Count > 1)
        {
            // ToList creates a copy
            allPoints.Add(curPoints.ToList());
            curPoints.Clear();
        }


    }

    private void pnlPaint_MouseMove(object sender, MouseEventArgs e)
    {
        if (e.Button != MouseButtons.Left) return;
        // here we should check if the distance is more than a minimum!
        curPoints.Add(e.Location);
        // let it show
        pnlPaint.Invalidate();
    }
    private void pnlPaint_Paint(object sender, PaintEventArgs e)
    {
        using (Pen pen = new Pen(Color.Black, 3f))
        {
            // regular edges:
            pen.MiterLimit = 1.5f
            // current lines
            if (curPoints.Count > 1) e.Graphics.DrawCurve(pen, curPoints.ToArray());
            // other lines
            foreach (List<Point> points in allPoints)
                if (points.Count > 1) e.Graphics.DrawCurve(pen, points.ToArray());
        }
    }}

    private void btn_undo_Click(object sender, EventArgs e)
    {
        if (allPoints.Count > 0)
        {
            allPoints.RemoveAt(allPoints.Count - 1);
            pnlPaint.Invalidate();
        }
    }

    private void btn_save_Click(object sender, EventArgs e)
    {
        string fileName = @"d:\sketch.png";
        Bitmap bmp = new Bitmap(pnlPaint.ClientSize.Width, pnlPaint.ClientSize.Width);
        pnlPaint.DrawToBitmap(bmp, pnlPaint.ClientRectangle);
        bmp.Save(fileName, ImageFormat.Png);
    }
  }

  class DrawPanel : Panel 
  {
     public DrawPanel ()
      {
        DoubleBuffered = true;
      }
  }

}

Just add one DrawPanel and two Buttons..

(I really should have used my Wacom, and a little more space..)

---

Update: Instead of a Panel, which is a Container control and not really meant to draw onto you can use a Picturebox or a Label (with Autosize=false); both have the DoubleBuffered property turned on out of the box and support drawing better than Panels do.

Answer 2

I found this solution Creating a Hand-Drawn effect using .NET

Maybe there is something more easy, for example something with transformations?