获取字符串的MD5值

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace ItCaseCommon
{
    public class MD5Helper
    {
        public static string GetStringMD5(string input, Encoding encode)
        {
            if (string.IsNullOrEmpty(input))
            {
                return null;
            }
            MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();
            byte[] data = md5Hasher.ComputeHash(encode.GetBytes(input));

            StringBuilder sBuilder = new StringBuilder();
            for (int i = 0; i < data.Length; i++)
            {
                sBuilder.Append(data[i].ToString("x2"));
            }
            return sBuilder.ToString();
        }
    }
}