C#

private void Form1_Paint(object sender, PaintEventArgs e)<br />
        {<br />
            int x1 = MousePosition.X;<br />
            int y1 = MousePosition.Y;<br />
<br />
            Graphics A = e.Graphics;<br />
            Pen BluePen = new Pen(Color.Blue, 3);<br />
            A.DrawLine(BluePen, 0, 0, x1, y1);<br />
<br />
            A.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;<br />
        }<br />
<br />
        private void Animator_Tick(object sender, EventArgs e)<br />
        {<br />
            this.Invalidate();<br />
        }