用C#画以正弦函数的轨迹画圆

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Threading;
using System.Text;
using System.Windows.Forms;

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

        private void button1_Click(object sender, EventArgs e)
        {
            Graphics DrawInterface = panel1.CreateGraphics();
            Pen MyPenRed = new Pen(Color.FromArgb(128, 255, 0, 0), 3);

            DrawInterface.DrawLine(MyPenBlack, 0, 300, 800, 300); //画直线

            int i;
            double angle1;
            float x1, y1;

            for (i = 0; i < 360; i += 20)
            {
                angle1 = (float)i * 2 * 3.14 / 360;
                x1 = (float)(300 + i);
                y1 = (float)(300 + 150 * Math.Sin(angle1));
                Rectangle TempRect = new Rectangle((int)x1, (int)y1, 30, 30);
                DrawInterface.DrawEllipse(MyPenRed, TempRect);
                Thread.Sleep(20);
             }
         }
    }
}