Log4Net 怎么用代码配置 每天生成一个文件

/// <summary>
        /// 使用文本记录异常日志
        /// </summary>
        /// <Author>Ryanding</Author>
        /// <date>2011-05-01</date>
        public static void LoadFileAppender()
        {
            string currentPath = AppDomain.CurrentDomain.BaseDirectory;
            string txtLogPath = string.Empty;
            string iisBinPath = AppDomain.CurrentDomain.RelativeSearchPath;

            if (!string.IsNullOrEmpty(iisBinPath))
                txtLogPath = Path.Combine(iisBinPath, string.Format("log/ErrorLog{0}.txt", DateTime.Now.ToString("yyyy-MM-dd")));
            else
                txtLogPath = Path.Combine(currentPath, string.Format("log/ErrorLog{0}.txt", DateTime.Now.ToString("yyyy-MM-dd")));
            
            FileAppender fileAppender = new FileAppender();
            fileAppender.Name = "LogFileAppender";
            fileAppender.File = txtLogPath;

            fileAppender.AppendToFile = true;
            PatternLayout patternLayout = new PatternLayout();
            patternLayout.ConversionPattern = "记录时间：%date 线程ID:[%thread] 日志级别：%-5level 出错类：%logger property:[%property{NDC}] - 错误描述：%message%newline";
            
            patternLayout.ActivateOptions();
            
            fileAppender.Layout = patternLayout;
            //选择UTF8编码，确保中文不乱码。
            fileAppender.Encoding = Encoding.UTF8;

            fileAppender.ActivateOptions();
            BasicConfigurator.Configure(fileAppender);

        }