C# Panel Graphic 绘图闪烁解决办法

用双缓冲的办法

1. 重载Panel类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    class Panel2 : Panel
    {
        public Panel2()
        {
            this.SetStyle(ControlStyles.UserPaint, true);
            this.SetStyle(ControlStyles.AllPaintingInWmPaint, true); 
            this.SetStyle(ControlStyles.DoubleBuffer, true);
            this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true); 
        }

        protected override CreateParams CreateParams
        {
            get
            {
                CreateParams cp = base.CreateParams;
                cp.ExStyle |= 0x02000000;
                return cp;
            }
        }
    }
}

2. 创建Panel2 的实例化对象

在Form1.Designer.cs文件里

3. 用 Panel.Paint 方法中的 Graphics 重绘

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

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        bool bDraw = false;
        public Form1()
        {
            InitializeComponent();

            timer1.Interval = 100;
            timer1.Start();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            bDraw = !bDraw;
            
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            if(bDraw)
            {
                panel1.Invalidate();
            }
        }

        void update(Panel panel, Graphics g)
        {
            Random rd = new Random();
            panel.BackColor = Color.FromArgb(rd.Next(0, 255), rd.Next(0, 255), rd.Next(0, 255));

            int nW = panel.Width;
            int nH = panel.Height;
            for (int i = 0; i < 20; i++)
            {
                g.DrawLine(new Pen(Brushes.Green, 2), new Point(i * (nW / 20), 0), new Point(i * (nW / 20), nH));
                g.DrawLine(new Pen(Brushes.Red, 2), new Point(0, i * (nH / 20)), new Point(nW, i * (nH / 20)));
            }
        }

        private void panel1_Paint(object sender, PaintEventArgs e)
        {
            update(panel1, e.Graphics);
        }
    }
}

4. 效果如图