log4net异步刷新 TextBox （试运行版）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using log4net.Core;


namespace log4net_richtextbox
{
    public partial class Form2 : Form
    {
        private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
        private bool logWatching = true;
        private log4net.Appender.MemoryAppender logger;
        private Thread logWatcher;


        public Form2()
        {
            InitializeComponent();

            this.Closing += new CancelEventHandler(Form1_Closing);
            logger = new log4net.Appender.MemoryAppender();

            log4net.Config.BasicConfigurator.Configure(logger);

            logWatcher = new Thread(new ThreadStart(LogWatcher));
            logWatcher.Start();

        }

        void Form1_Closing(object sender, CancelEventArgs e)
        {
            logWatching = false;
            logWatcher.Join();

        }

        delegate void delOneStr(string log);
        void AppendLog(string _log)
        {
            if (txtLog.InvokeRequired)
            {
                delOneStr dd = new delOneStr(AppendLog);
                txtLog.Invoke(dd, new object[] { _log });
            }
            else
            {
                StringBuilder builder;
                if (txtLog.Lines.Length > 99)
                {
                    builder = new StringBuilder(txtLog.Text);
                    builder.Remove(0, txtLog.Text.IndexOf('\r', 3000) + 2);
                    builder.Append(_log);
                    txtLog.Clear();
                    txtLog.AppendText(builder.ToString());
                }
                else
                {
                    txtLog.AppendText(_log);
                }
            }

        }

        private void LogWatcher()
        {
            while (logWatching)
            {
                LoggingEvent[] events = logger.GetEvents();
                if (events != null && events.Length > 0)
                {
                    logger.Clear();
                    foreach (LoggingEvent ev in events)
                    {
                        string line = ev.LoggerName + ": " + ev.RenderedMessage + "\r\n";
                        AppendLog(line);
                    }
                }
                Thread.Sleep(500);
            }
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            log.Info(DateTime.Now.ToString());
        }

    }

}