我的Base64编码，去掉等号特殊字符

  1     /// 
自定义包含指定字符的base64工具
  2     internal static class Base64Helper
  3     {
  4         static readonly string base64Table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-";
  5         static readonly int[] base64Index = new int[]
  6         {
  7             -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  8             -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
  9             -1,63,-1,-1,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-1,-1,-1,-1,0,1,
 10             2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,
 11             -1,-1,-1,62,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,
 12             43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1,-1
 13         };
 14         public static byte[] FromBase64String(string inData)
 15         {
 16             int inDataLength = inData.Length;
 17             int lengthmod4 = inDataLength % 4;
 18             int calcLength = (inDataLength - lengthmod4);
 19             byte[] outData = new byte[inDataLength / 4 * 3 + 3];
 20             int j = 0;
 21             int i;
 22             int num1, num2, num3, num4;
 23 
 24             for (i = 0; i < calcLength; i += 4, j += 3)
 25             {
 26                 num1 = base64Index[inData[i]];
 27                 num2 = base64Index[inData[i + 1]];
 28                 num3 = base64Index[inData[i + 2]];
 29                 num4 = base64Index[inData[i + 3]];
 30 
 31                 outData[j] = (byte)((num1 << 2) | (num2 >> 4));
 32                 outData[j + 1] = (byte)(((num2 << 4) & 0xf0) | (num3 >> 2));
 33                 outData[j + 2] = (byte)(((num3 << 6) & 0xc0) | (num4 & 0x3f));
 34             }
 35             i = calcLength;
 36             switch (lengthmod4)
 37             {
 38                 case 3:
 39                     num1 = base64Index[inData[i]];
 40                     num2 = base64Index[inData[i + 1]];
 41                     num3 = base64Index[inData[i + 2]];
 42 
 43                     outData[j] = (byte)((num1 << 2) | (num2 >> 4));
 44                     outData[j + 1] = (byte)(((num2 << 4) & 0xf0) | (num3 >> 2));
 45                     j += 2;
 46                     break;
 47                 case 2:
 48                     num1 = base64Index[inData[i]];
 49                     num2 = base64Index[inData[i + 1]];
 50 
 51                     outData[j] = (byte)((num1 << 2) | (num2 >> 4));
 52                     j += 1;
 53                     break;
 54             }
 55             Array.Resize(ref outData, j);
 56             return outData;
 57         }
 58         public static string ToBase64String(byte[] inData)
 59         {
 60             int inDataLength = inData.Length;
 61             int outDataLength = (int)(inDataLength / 3 * 4) + 4;
 62             char[] outData = new char[outDataLength];
 63 
 64             int lengthmod3 = inDataLength % 3;
 65             int calcLength = (inDataLength - lengthmod3);
 66             int j = 0;
 67             int i;
 68 
 69             for (i = 0; i < calcLength; i += 3, j += 4)
 70             {
 71                 outData[j] = base64Table[inData[i] >> 2];
 72                 outData[j + 1] = base64Table[((inData[i] & 0x03) << 4) | (inData[i + 1] >> 4)];
 73                 outData[j + 2] = base64Table[((inData[i + 1] & 0x0f) << 2) | (inData[i + 2] >> 6)];
 74                 outData[j + 3] = base64Table[(inData[i + 2] & 0x3f)];
 75             }
 76 
 77             i = calcLength;
 78             switch (lengthmod3)
 79             {
 80                 case 2:
 81                     outData[j] = base64Table[inData[i] >> 2];
 82                     outData[j + 1] = base64Table[((inData[i] & 0x03) << 4) | (inData[i + 1] >> 4)];
 83                     outData[j + 2] = base64Table[(inData[i + 1] & 0x0f) << 2];
 84                     j += 3;
 85                     break;
 86                 case 1:
 87                     outData[j] = base64Table[inData[i] >> 2];
 88                     outData[j + 1] = base64Table[(inData[i] & 0x03) << 4];
 89                     j += 2;
 90                     break;
 91             }
 92             return new string(outData, 0, j);
 93         }
 94         public static string Base64Encode(string source)
 95         {
 96             byte[] barray = Encoding.Default.GetBytes(source);
 97             return Base64Helper.ToBase64String(barray);
 98         }
 99         public static string Base64Decode(string source)
100         {
101             byte[] barray = Base64Helper.FromBase64String(source);
102             return Encoding.Default.GetString(barray);
103         }
104     }

 

转载于:https://www.cnblogs.com/softcreator/articles/softcreator_8627573.html