using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        internal const int WM_PAINT = 0xF;
        [StructLayout(LayoutKind.Sequential)]
        internal struct RECT
        {
            internal int Left;
            internal int Top;
            internal int Right;
            internal int Bottom;
        }
        [StructLayout(LayoutKind.Sequential)]
        internal struct PAINTSTRUCT
        {
            internal int hdc;
            internal int fErase;
            internal RECT rcPaint;
            internal int fRestore;
            internal int fIncUpdate;
            internal byte rgbReserved;
        }

        [DllImport("user32.dll")]
        internal static extern int BeginPaint(int hwnd, ref PAINTSTRUCT lpPaint);
        [DllImport("user32.dll")]
        internal static extern int EndPaint(int hwnd, ref PAINTSTRUCT lpPaint);

        public Form1()
        {
            InitializeComponent();
        }
        protected override void WndProc(ref Message m)
        {
            int hWnd = this.Handle.ToInt32();
            if (m.Msg == WM_PAINT)
            {
                Console.WriteLine("WM_PAINT");
                int dummy = 0;
                Console.WriteLine("dummy = {0}", dummy);
                PAINTSTRUCT ps = new PAINTSTRUCT();
                BeginPaint(hWnd, ref ps);
                Console.WriteLine("dummy = {0}", dummy);
                // we can draw smth. here in real application
                EndPaint(hWnd, ref ps);
            }
            else
            {
                base.WndProc(ref m);
            }
        }
    }
}