C#实现MD5

 1 using System;
 2 using System.Collections.Generic;
 3 using System.IO;
 4 using System.Linq;
 5 using System.Security.Cryptography;
 6 using System.Text;
 7 using System.Threading.Tasks;
 8 
 9 namespace ConsoleApplication1
10 {
11     public class MD5Helper
12     {
13         /// <summary>
14         /// 计算字节数组的 MD5 值
15         /// </summary>
16         /// <param name="buffer"></param>
17         /// <returns></returns>
18         public static string CalcMD5(byte[] buffer)
19         {
20             using (MD5 md5 = MD5.Create())
21             {
22                 byte[] md5Bytes = md5.ComputeHash(buffer);
23                 return BytesToString(md5Bytes);
24             }
25         }
26 
27         /// <summary>
28         /// 将得到的 MD5 字节数组转成 字符串
29         /// </summary>
30         /// <param name="md5Bytes"></param>
31         /// <returns></returns>
32         private static string BytesToString(byte[] md5Bytes)
33         {
34             StringBuilder sb = new StringBuilder();
35             for (int i = 0; i < md5Bytes.Length; i++)
36             {
37                 sb.Append(md5Bytes[i].ToString("X2"));
38             }
39             return sb.ToString();
40         }
41 
42         /// <summary>
43         /// 计算字符串的 MD5 值
44         /// </summary>
45         /// <param name="str"></param>
46         /// <returns></returns>
47         public static string CalcMD5(string str)
48         {
49             byte[] buffer = Encoding.UTF8.GetBytes(str);
50             return CalcMD5(buffer);
51         }
52 
53         /// <summary>
54         /// 计算流的 MD5 值
55         /// </summary>
56         /// <param name="stream"></param>
57         /// <returns></returns>
58         public static string CalcMD5(Stream stream)
59         {
60             using (MD5 md5 = MD5.Create())
61             {
62                 byte[] buffer = md5.ComputeHash(stream);
63                 return BytesToString(buffer);
64             }
65         }
66     }
67 }