在c#中绘制一个x^2+sinx的图像的程序是什么

在c#中绘制一个x^2+sinx的图像的程序是什么

新建Form，粘贴如下代码
    public partial class Form1 : Form
    {
        PictureBox p;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            p = new PictureBox();
            p.Dock = DockStyle.Fill;
            this.Controls.Add(p);
            p.Paint += this.p_Paint;
        }

        private void p_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            for (float x = -30; x <= 30; x += 0.01f)
            {
                PointF p = new PointF(
                    (float)x, x * x + (float)Math.Sin(x));
                this.DrawPoint(g, ref p);
            }
        }

        private void DrawPoint(Graphics g, ref PointF p)
        {
            p.X = p.X + this.p.Width / 2;
            p.Y = this.p.Height / 2 - p.Y;
            g.DrawEllipse(new Pen(Color.Red), 
                new RectangleF(p, new SizeF(1, 1)));
        }
    }