Why doesn't my Windows Form get redrawn when the window is resized?

Question

I have a simple Form such as the following:

using System;
using System.Drawing;
using System.Windows.Forms;

namespace PaintTest
{
   class PaintTest : Form
   {
      int _counter = 0;

      [STAThread]
      static void Main()
      {
         Application.Run(new PaintTest());
      }

      protected override void OnPaint(PaintEventArgs e)
      {
         e.Graphics.DrawString(_counter.ToString(), new Font(FontFamily.GenericSerif, 10.0f), Brushes.Blue, 10.0f, 10.0f);
         _counter++;
      }
   }
}

When the window is resized, the counter doesn't appear to update on the screen, even though OnPaint() is getting called and the counter incremented. How do I make the Form repaint itself as the window is resized?

Answer 1

Add the following to your class, e.g. in its constructor:

SetStyle(ControlStyles.ResizeRedraw, true);