C# 操作文件类，文件夹存在判断，创建，文件内容读写。

 1 class FileOperate
 2     {
 3         public static void Main()
 4         {
 5             try
 6             {
 7                 FileOperate fo = new FileOperate();
 8                 string path = @"D:\MrSong1";    //正常路径
 9                 string illeglePath = @"D:\111>";    //含有非法字符
10                 string overLengthPath = @""+fo.GetLongPath();   //路径超长
11                
12                 fo.DirectoryNomal(path);  //正常  
13                 Console.WriteLine("创建路径：" + path);
14                 Directory.CreateDirectory(path);    //创建
15                 fo.DirectoryNomal(path);    
16                 Console.WriteLine("删除路劲：" + path);
17                 Directory.Delete(path); //删除
18                 fo.DirectoryNomal(path);
19                 DirectoryInfo dirInfo = new DirectoryInfo(path);
20                 if (!dirInfo.Exists)
21                 {
22                     dirInfo.Create();   //创建路径
23                 }
24                 dirInfo.Delete();
25                 fo.DirectoryNomal(illeglePath); //报“路径中存在非法字符异常”，下面的方法不执行
26                 fo.DirectoryNomal(overLengthPath);  //修改illegalPath为正确路径后，执行此方法，报”指定路径名过长“
27             }
28             catch (Exception ex)
29             {
30                 Console.WriteLine(ex);
31             }
32             Console.ReadKey();
33         }
34 
35         private void DirectoryNomal(string path)
36         {
37             if (Directory.Exists(path))
38             {
39                 Console.WriteLine("Directory类方法判断：存在路径");
40             }
41             else
42             {
43                 Console.WriteLine("Directory类方法判断：不存在" + path);
44             }
45             DirectoryInfo di = new DirectoryInfo(path);
46             if (di.Exists)
47             {
48                 Console.WriteLine("DirectoryInfo属性判断：存在路径" + path);
49             }
50             else
51             {
52                 Console.WriteLine("DirectoryInfo属性判断：不存在路径");
53             }
54         }
55 
56         private string GetLongPath()
57         {
58             string path = "";
59             char[] Pattern = new char[] { ‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘, ‘6‘, ‘7‘, ‘8‘, ‘9‘, ‘A‘, ‘B‘, ‘C‘, ‘D‘, ‘E‘, ‘F‘, ‘G‘, ‘H‘, ‘I‘, ‘J‘, ‘K‘, ‘L‘, ‘M‘, ‘N‘, ‘O‘, ‘P‘, ‘Q‘, ‘R‘, ‘S‘, ‘T‘, ‘U‘, ‘V‘, ‘W‘, ‘X‘, ‘Y‘, ‘Z‘ };
60             System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));
61             int i=0;
62             int n = Pattern.Length;
63           
64             while (i <= 257)
65             {
66                 int rnd = random.Next(0, n);
67                 path += Pattern[rnd];
68                 i++;
69             }
70             return path;
71         }
72     }