private Point LastPoint { get; set; } private void Form1_MouseMove(object sender, MouseEventArgs e) { label2.Text = "x:" + e.X; label3.Text = "y:" + e.Y; if (drawing == true) { Graphics graphics = CreateGraphics(); SolidBrush brush = new SolidBrush(color); if (LastPoint == null) graphics.FillEllipse(brush, e.X, e.Y, size, size); else graphics.DrawLine(new Pen(brush, size), LastPoint, new Point(e.X, e.Y)); } LastPoint = new Point(e.X, e.Y); }