C#保存日志文件到txt中,可追加保存

 1         /// <summary>
 2         /// 输出指定信息到文本文件
 3         /// </summary>
 4         /// <param name="msg">输出信息</param>
 5         public void WriteMessage(string msg, string userName)
 6         {
 7             try
 8             {
 9 
10                 string mainPath = "F:\\log\\";//日志文件路径&配置到Config文件中直接获取
11                 string path = mainPath;
12                 string filename = DateTime.Now.ToString("yyyyMMdd") + ".txt";//文件名
13                 string year = DateTime.Now.ToString("yyyy");//年
14                 string month = DateTime.Now.ToString("MM");//月
15 
16                 //判断log文件路径是否存在，不存在则创建文件夹 
17                 if (!System.IO.Directory.Exists(path))
18                 {
19                     System.IO.Directory.CreateDirectory(path);//不存在就创建目录 
20                 }
21 
22                 path += year + "\\";
23                 //判断年度文件夹是否存在，不存在则创建文件夹 
24                 if (!System.IO.Directory.Exists(path))
25                 {
26                     System.IO.Directory.CreateDirectory(path);//不存在就创建目录 
27                 }
28 
29                 path += month + "\\";
30                 //判断月度文件夹是否存在，不存在则创建文件夹 
31                 if (!System.IO.Directory.Exists(path))
32                 {
33                     System.IO.Directory.CreateDirectory(path);//不存在就创建目录 
34                 }
35 
36                 //拼接完整文件路径
37                 path += filename;
38                 if (!File.Exists(path))
39                 {
40                     //文件不存在，新建文件
41                     FileStream fs = new FileStream(path, FileMode.OpenOrCreate);
42                     StreamWriter sw = new StreamWriter(fs);
43                     sw.Close();
44                 }
45 
46                 using (FileStream fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write))
47                 {
48                     using (StreamWriter sw = new StreamWriter(fs))
49                     {
50                         sw.BaseStream.Seek(0, SeekOrigin.End);
51                         //sw.WriteLine("------------------------------------------------------------------------ Info Start ");
52                         sw.WriteLine("操作时间：" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
53                         sw.WriteLine("操作人：" + userName);
54                         sw.WriteLine("Message：{0}\n", msg, DateTime.Now);
55                         sw.WriteLine("------------------------------------------------------------------------ ");
56                         Console.WriteLine("\n");
57                         sw.Flush();
58                     }
59                 }
60 
61                 //当前月份
62                 int totalmonth = int.Parse(month);
63                 int totalyear = int.Parse(year);
64                 int tmonth = 6;//保留日志时长，月度单位
65                 DateTime date;
66                 string datestring = "";
67 
68                 DirectoryInfo dyInfo = new DirectoryInfo(mainPath);
69                 //删除历史数据，保留6个月日志
70                 if (totalmonth < tmonth)
71                 {
72                     //删除前一年totalmonth+6月份之前的数据
73                     datestring = (totalyear - 1).ToString() + "-" + (totalmonth + tmonth).ToString().PadLeft(2, ‘0‘) + "-" + "01 00:00:00";
74 
75                 }
76                 else
77                 {
78                     //删除当年6个月前的数据
79                     datestring = (totalyear).ToString() + "-" + (totalmonth - tmonth).ToString().PadLeft(2, ‘0‘) + "-" + "01 00:00:00";
80                 }
81                 date = Convert.ToDateTime(datestring);
82                 //获取文件夹下所有的文件
83                 foreach (FileInfo feInfo in dyInfo.GetFiles())
84                 {
85                     //判断文件日期是否小于今天，是则删除
86                     if (feInfo.CreationTime < date)
87                         feInfo.Delete();
88                 }
89             }
90             catch (Exception)
91             {
92             }
93         }