写入文件txt

         FileStream fs = new FileStream(@"d:\service.txt", FileMode.OpenOrCreate, FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs); 
            using ( fs)
            {
                using (sw)
                {
                    sw.BaseStream.Seek(0, SeekOrigin.End);
                    sw.WriteLine("WindowsService: Service Started" + DateTime.Now.ToString() + "\n");
                    sw.Flush(); 
                }
            }