C#快速写文件

            var dir = Environment.CurrentDirectory + "\\Logs";
            if (Directory.Exists(dir))
            {
                Directory.CreateDirectory(dir);
            }
            var logName = string.Concat(dir, DateTime.Now.ToString(".yyyyMMdd"), ".log");
            if (!File.Exists(logName))
            {
                File.Create(logName).Close();
            }
            var guidS = Guid.NewGuid().ToString();
            var guidSReplace = guidS.Replace("-", string.Empty);
            File.WriteAllText(logName, string.Concat(guidS.Length.ToString(), "-", guidSReplace.Length.ToString(), "-", guidS));