转换byte(十进制)为图形（大小写字母，符号）

/**
 * 转换byte(十进制)为字母
 */

public static string bytetoletter (byte[] chars) {
   string letter = "";
   for (int i = 0; i < chars.length; i++) {
      switch (chars[i]) {
         case 45:
            letter += "-";
            break;
         case 46:
            letter += ".";
            break;
         case 47:
            letter += "/";
            break;
         case 48:
            letter += "0";
            break;
         case 49:
            letter += "1";
            break;
         case 50:
            letter += "2";
            break;
         case 51:
            letter += "3";
            break;
         case 52:
            letter += "4";
            break;
         case 53:
            letter += "5";
            break;
         case 54:
            letter += "6";
            break;
         case 55:
            letter += "7";
            break;
         case 56:
            letter += "8";
            break;
         case 57:
            letter += "9";
            break;
         case 65:
            letter += "a";
            break;
         case 66:
            letter += "b";
            break;
         case 67:
            letter += "c";
            break;
         case 68:
            letter += "d";
            break;
         case 69:
            letter += "e";
            break;
         case 70:
            letter += "f";
            break;
         case 71:
            letter += "g";
            break;
         case 72:
            letter += "h";
            break;
         case 73:
            letter += "i";
            break;
         case 74:
            letter += "j";
            break;
         case 75:
            letter += "k";
            break;
         case 76:
            letter += "l";
            break;
         case 77:
            letter += "m";
            break;
         case 78:
            letter += "n";
            break;
         case 79:
            letter += "o";
            break;
         case 80:
            letter += "p";
            break;
         case 81:
            letter += "q";
            break;
         case 82:
            letter += "r";
            break;
         case 83:
            letter += "s";
            break;
         case 84:
            letter += "t";
            break;
         case 85:
            letter += "u";
            break;
         case 86:
            letter += "v";
            break;
         case 87:
            letter += "w";
            break;
         case 88:
            letter += "x";
            break;
         case 89:
            letter += "y";
            break;
         case 90:
            letter += "z";
            break;
         case 95:
            letter += "a";
            break;
         case 98:
            letter += "b";
            break;
         case 99:
            letter += "c";
            break;
         case 100:
            letter += "d";
            break;
         case 101:
            letter += "e";
            break;
         case 102:
            letter += "f";
            break;
         case 103:
            letter += "g";
            break;
         case 104:
            letter += "h";
            break;
         case 105:
            letter += "i";
            break;
         case 106:
            letter += "j";
            break;
         case 107:
            letter += "k";
            break;
         case 108:
            letter += "l";
            break;
         case 109:
            letter += "m";
            break;
         case 110:
            letter += "n";
            break;
         case 111:
            letter += "o";
            break;
         case 112:
            letter += "p";
            break;
         case 113:
            letter += "q";
            break;
         case 114:
            letter += "r";
            break;
         case 115:
            letter += "s";
            break;
         case 116:
            letter += "t";
            break;
         case 117:
            letter += "u";
            break;
         case 118:
            letter += "v";
            break;
         case 119:
            letter += "w";
            break;
         case 120:
            letter += "x";
            break;
         case 121:
            letter += "y";
            break;
         case 122:
            letter += "z";
            break;
         default:
            letter += "";
      }
   }
   return letter;
}