c# - 如何为面板进行双缓冲？

Question

我正在尝试进行双缓冲以消除闪烁，但重新绘制图像闪烁。我需要在新位置的栏中以周期性方式重绘图像，它对我有用。但重绘时闪烁非常明显。请帮忙。

namespace CockroachRunning
{
    public partial class Form1 : Form
    {
        Random R = new Random();
        Semaphore s1 = new Semaphore(2, 4);
        Bitmap cockroachBmp = new Bitmap(Properties.Resources.cockroach, new Size(55, 50));
        List<Point> cockroaches = new List<Point>();
        public Form1()
        {
            InitializeComponent();
            this.DoubleBuffered = true;
            cockroaches.Add(new Point(18,13));
            Thread t1 = new Thread(Up);
            t1.Start();
        }
        public void Up()
        {
            while (true) 
            {
                s1.WaitOne();
                int distance = R.Next(1, 6);
                for (int i = 0; i < distance; i++)
                {
                    if (cockroaches[0].Y - 1 > -1)
                    {
                        cockroaches[0] = new Point(cockroaches[0].X, cockroaches[0].Y - 1);
                        panel1.Invalidate();                        
                    }
                }
                s1.Release();
                Thread.Sleep(100);
            }
        }
        private void panel1_Paint(object sender, PaintEventArgs e)
        {
            Image i = new Bitmap(panel1.ClientRectangle.Width, panel1.ClientRectangle.Height);
            Graphics g = Graphics.FromImage(i);
            Graphics displayGraphics = e.Graphics;
            g.DrawImage(cockroachBmp, cockroaches[0]);
            displayGraphics.DrawImage(i, panel1.ClientRectangle);
        }
    }
}

Answer 1

为了摆脱闪烁，我使用以下设置来配置控件的行为方式：

base.DoubleBuffered = true;

SetStyle(ControlStyles.AllPaintingInWmPaint, true);
SetStyle(ControlStyles.ResizeRedraw, true);
SetStyle(ControlStyles.UserPaint, true);
SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
UpdateStyles();

我在Control派生类的构造函数中调用它。我不确定这是否也适用于表单，但我想它确实有效。

然后在void OnPaintBackground(PaintEventArgs e)（擦除客户区）和void OnPaint(PaintEventArgs e)（实际绘图）中完成绘图。