1 <appSettings>
2     <add key="LogPath" value="http://www.mamicode.com/H:/Logs" />
3 </appSettings>

 1   public class SystemLog
 2     {
 3         public static void WriteLogLine(string exceptionMessage)
 4         {
 5             string path = string.Empty;
 6             try
 7             {
 8                path = ConfigurationManager.AppSettings["LogPath"];
 9             }
10             catch (Exception)
11             {
12                 path = @"c:\temp";
13             }
14             if (string.IsNullOrEmpty(path))
15                 path = @"c:\temp";
16             try
17             {
18                 //如果日志目录不存在,则创建该目录
19                 if (!Directory.Exists(path))
20                 {
21                     Directory.CreateDirectory(path);
22                 }
23                 string logFileName = path + "\\程序日志_" + DateTime.Now.ToString("yyyy_MM_dd_HH") + ".log";
24                 StringBuilder logContents = new StringBuilder();
25                 logContents.AppendLine(exceptionMessage);
26                 //当天的日志文件不存在则新建，否则追加内容
27                 StreamWriter sw = new StreamWriter(logFileName, true, System.Text.Encoding.Unicode);
28                 sw.Write(DateTime.Now.ToString("yyyy-MM-dd hh:mm:sss") + " " + logContents.ToString());
29                 sw.Flush();
30                 sw.Close();
31             }
32             catch (Exception)
33             {
34             }
35         }
36     }

SystemLog.WriteLogLine("======>程序开始执行");//记录程序开始执行的时间