C#記錄日志到文本文件

在配置文件中添加日志文件的存放路徑：

1 <appSettings>
2     <add key="LogPath" value="H:\Logs" />
3 </appSettings>

封裝一個記錄日志的類:

  public class SystemLog
    {
        public static void WriteLogLine(string exceptionMessage)
        {
            string path = string.Empty;
            try
            {
               path = ConfigurationManager.AppSettings["LogPath"];
            }
            catch (Exception)
            {
                path = @"c:\temp";
            }
            if (string.IsNullOrEmpty(path))
                path = @"c:\temp";
            try
            {
                //如果日志目錄不存在,則創建該目錄
                if (!Directory.Exists(path))
                {
                    Directory.CreateDirectory(path);
                }
                string logFileName = path + "\\程序日志_" + DateTime.Now.ToString("yyyy_MM_dd_HH") + ".log";
                StringBuilder logContents = new StringBuilder();
                logContents.AppendLine(exceptionMessage);
                //當天的日志文件不存在則新建，否則追加內容
                StreamWriter sw = new StreamWriter(logFileName, true, System.Text.Encoding.Unicode);
                sw.Write(DateTime.Now.ToString("yyyy-MM-dd hh:mm:sss") + " " + logContents.ToString());
                sw.Flush();
                sw.Close();
            }
            catch (Exception)
            {
            }
        }
    }

 在程序中使用日志類：

SystemLog.WriteLogLine("======>程序開始執行");//記錄程序開始執行的時間