What is the best way to make animation in GDI+?

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.Threading;
using System.Diagnostics;

namespace _123
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            bitmap = new Bitmap(500, 500);
            g = Graphics.FromImage(bitmap);
            stopwatch = new Stopwatch();

            this.DoubleBuffered = true;
            this.Paint += Draw;

            stopwatch.Start();
            (new Thread(new ThreadStart(Drawing_Thread))).Start();
        }

        Stopwatch stopwatch;

        Bitmap bitmap;
        Graphics g;

        int x = 20;
        int add = 1;

        private void Drawing_Thread()
        {
            while (true)
                if (stopwatch.Elapsed.Milliseconds >= 1)
                {
                    stopwatch.Stop();
                    if (x == 300) add *= -1;
                    if (x == 0) add *= -1;
                    g.Clear(Color.Transparent);
                    g.FillRectangle(Brushes.Red, x += add, 50, 100, 100);

                    this.Invoke(new Action(this.Invalidate));
                    stopwatch.Restart();
                }
        }

        private void Draw(object sender, PaintEventArgs e)
        {
            e.Graphics.DrawImage(bitmap, 0, 0);
        }
    }
}