Form.ResizeRedraw
using System; using System.Drawing; using System.Drawing.Printing; using System.Windows.Forms; class PrintableForm: Form { public static void Main() { Application.Run(new PrintableForm()); } public PrintableForm() { ResizeRedraw = true; } protected override void OnPaint(PaintEventArgs pea) { DoPage(pea.Graphics, ForeColor,ClientSize.Width, ClientSize.Height); } protected void DoPage(Graphics grfx, Color clr, int cx, int cy) { Pen pen = new Pen(clr); grfx.DrawLine(pen, 0, 0, cx - 1, cy - 1); grfx.DrawLine(pen, cx - 1, 0, 0, cy - 1); } }