写入文件日志方式

         private static readonly object _LockObject = new object();
        private static Random _Random = new Random();
        private static DateTime _LastDeleteTime = DateTime.Now;

       //文件夹名称 _FilePath=@"Logs"    文件名  _FileName, 
        public static void WriteLog(string _FilePath, string _FileName, string _Msg)
        {
            lock (_LockObject)
            {
                try
                {
                    var _Path = AppDomain.CurrentDomain.BaseDirectory + _FilePath + @"";
                    if (!Directory.Exists(_Path))
                    {
                        Directory.CreateDirectory(_Path);
                    }
                    _FileName = _FileName + "_" + DateTime.Now.ToString("yyyy-MM-dd") + ".txt";

if (_Random.Next(10) >= 9 && File.Exists(_Path + _FileName))
                    {
                        FileInfo fileInfo = new FileInfo(_Path + _FileName);
                        if (fileInfo.Length > 10485760)//10M
                        {
                            fileInfo.MoveTo(_Path + _FileName.Replace(".", string.Format("_{0}.", DateTime.Now.ToString("HHmmss"))));
                        }
                    }
                    System.IO.StreamWriter _Writer = new System.IO.StreamWriter
                         (
                            _Path + _FileName,
                            true,
                            System.Text.Encoding.Default
                         );
                    _Writer.WriteLine(string.Concat("[", DateTime.Now.ToString("HH:mm:ss"), "]  ", _Msg, "

"));
                    _Writer.Close();
//  删除超过15天的日志
                    if ((DateTime.Now.Day != _LastDeleteTime.Day))
                    {
                        _LastDeleteTime = DateTime.Now;
                        var files = Directory.GetFiles(_Path);

                        foreach (var file in files.Where(t => t.EndsWith(".txt")))
                        {
                            var fileInfo = new FileInfo(file);
                            if (!IsRealMatch(fileInfo.Name.ToLower(), "_[0-9]{4}[-][0-9]{2}[-][0-9]{2}[^.]{0,20}[.]txt"))
                            {
                                continue;
                            }
                            if ((DateTime.Now - fileInfo.LastWriteTime).TotalDays > 15)
                            {
                                File.Delete(file);
                            }
                        }
                    }
                   

                }
catch 
                { }
            }
        }
public static bool IsRealMatch(string inputInfo, string strInfo)
        {
            return IsMatch(inputInfo, strInfo, RegexOptions.IgnoreCase | RegexOptions.Singleline);
        }
 public static bool IsMatch(string inputInfo, string strInfo, RegexOptions options)
        {
            return Regex.IsMatch(inputInfo, strInfo, options);
        }