自定义了一个继承panel的类,但是却不能绘图了,该怎么处理

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;

namespace 贪吃蛇
{
    public class PanelNew : Panel
    {
        public PanelNew()
            : base()
        {
            SetStyle(ControlStyles.UserPaint, true);
            SetStyle(ControlStyles.AllPaintingInWmPaint, true); // 禁止擦除背景. 
            SetStyle(ControlStyles.DoubleBuffer, true); // 双缓冲 
            this.UpdateStyles();

            //SetStyle(ControlStyles.UserPaint | ControlStyles.DoubleBuffer | ControlStyles.AllPaintingInWmPaint | ControlStyles.ResizeRedraw, true);
            //this.UpdateStyles();
        }
    }
}