C# 寫日誌

class Log
    {        
        public static void Write(string str)
        {
            FileStream fs = null;
            string LogDir = Directory.GetCurrentDirectory() + "\\log\\";
            Directory.CreateDirectory(LogDir);
            string fileName = LogDir + DateTime.Now.ToString("yyyyMMdd") + ".txt";  
           
            //將待寫的入數據從字符串轉換爲字節數組  
            Encoding encoder = Encoding.UTF8;
            byte[] bytes = encoder.GetBytes(DateTime.Now.ToString("hh:mm:ss") + ": " + str + Environment.NewLine);  
            try  
            {
                fs = File.OpenWrite(fileName);  
                //設定書寫的開始位置爲文件的末尾  
                fs.Position = fs.Length;  
                //將待寫入內容追加到文件末尾  
                fs.Write(bytes, 0, bytes.Length);
                // fs.Write();
            }  
            catch (Exception ex)  
            {  
                Console.WriteLine("文件打開失敗{0}", ex.ToString());  
            }  
            finally  
            {  
                fs.Close();  
            }  
        }
    }