C# obsluga myszki / rysowanie w oknie.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        private int x, y;
        private bool rysuj;


        private void mysz_wcisnieta(Object Sender, MouseEventArgs e)
        {

            rysuj = true;
            x = e.X;
            y = e.Y;

        }
        private void mysz_niewcisnieta(Object Sender, MouseEventArgs e)
        {

            rysuj = false;
        }
        public Form1()
        {

            MouseDown += new MouseEventHandler(mysz_wcisnieta);
            MouseUp += new MouseEventHandler(mysz_niewcisnieta);
            MouseMove += new MouseEventHandler(delegate(Object Sender, MouseEventArgs e)
            {
                if (rysuj == true)
                {
                    Graphics g = CreateGraphics();
                    g.DrawLine(Pens.Blue, x, y, e.X, e.Y);
                    x = e.X;
                    y = e.Y;
                }
            });
            InitializeComponent();
        }

    }
}