C#字符串自增自减算法

本文URL：http://www.cnblogs.com/CUIT-DX037/p/6770535.html
实现字符串自增和自减运算：
1.数字从 0-9 变化；
2.字母从 A-Z、a-z 变化；
3.其它字符跳过；
4.以上变化依据其Ascii码值；
  1     /// <summary>
  2     /// 字符串运算
  3     /// </summary>
  4     public class StringOperation
  5     {
  6 
  7 
  8         /// <summary>
  9         /// 通过ASCII码值，对字符串自增1
 10         /// </summary>
 11         /// <param name="pStr">输入字符串</param>
 12         /// <returns></returns>
 13         public static string StringIncreaseOne(string pStr)
 14         {
 15             var vRetStr = pStr;
 16             if (0 == pStr.Length)
 17             {
 18                 vRetStr = "1";
 19             }
 20             else
 21             {
 22                 // 将最后一个字符与之前的字符串分开
 23                 string vOtherStr = pStr.Substring(0, pStr.Length - 1);
 24                 int vIntChar = (int)pStr[pStr.Length - 1]; //转ASCII码值
 25                 if (48 <= vIntChar && vIntChar <= 57) //是数字（0 - 9）
 26                 {
 27                     vIntChar++; //自增1
 28                     if (vIntChar == 58) // 进一位
 29                     {
 30                         vIntChar = 48;
 31                         vOtherStr = StringIncreaseOne(vOtherStr);
 32                     }
 33                 }
 34                 else if (65 <= vIntChar && vIntChar <= 90) //是字母（A - Z）
 35                 {
 36                     vIntChar++; //自增1
 37                     if (vIntChar == 91) 
 38                     {
 39                         vIntChar = 65;
 40                         vOtherStr = StringIncreaseOne(vOtherStr);
 41                     }
 42                 }
 43                 else if (97 <= vIntChar && vIntChar <= 122) //是字母（a - z）
 44                 {
 45                     vIntChar++; //自增1
 46                     if (vIntChar == 123)
 47                     {
 48                         vIntChar = 97;
 49                         vOtherStr = StringIncreaseOne(vOtherStr); 
 50                     }
 51                 }
 52                 else // 其它字符 -> 跳过
 53                 {
 54                     vOtherStr = StringIncreaseOne(vOtherStr);
 55                 }
 56                 vRetStr = vOtherStr + (char)vIntChar;
 57             }
 58             return vRetStr;
 59         }
 60 
 61         /// <summary>
 62         /// 通过ASCII码值，对字符串自减1
 63         /// </summary>
 64         /// <param name="pStr">输入字符串</param>
 65         /// <returns></returns>
 66         public static string StringReducingOne(string pStr)
 67         {
 68             var vRetStr = pStr;
 69             if (0 == pStr.Length)
 70             {
 71                 vRetStr = "9";
 72             }
 73             else
 74             {
 75                 string vOtherStr = pStr.Substring(0, pStr.Length - 1);
 76                 int vIntChar = (int)pStr[pStr.Length - 1]; //转ASCII码值
 77                 if (48 <= vIntChar && vIntChar <= 57) //是数字（0 - 9）
 78                 {
 79                     vIntChar--;
 80                     if (vIntChar == 47)
 81                     {
 82                         vIntChar = 57;
 83                         vOtherStr = StringReducingOne(vOtherStr);
 84                     }
 85                 }
 86                 else if (65 <= vIntChar && vIntChar <= 90) //是数字（A - Z）
 87                 {
 88                     vIntChar--; 
 89                     if (vIntChar == 64)
 90                     {
 91                         vIntChar = 90;
 92                         vOtherStr = StringReducingOne(vOtherStr);
 93                     }
 94                 }
 95                 else if (97 <= vIntChar && vIntChar <= 122) //是数字（a - z）
 96                 {
 97                     vIntChar--;
 98                     if (vIntChar == 96)
 99                     {
100                         vIntChar = 122;
101                         vOtherStr = StringReducingOne(vOtherStr);
102                     }
103                 }
104                 else // 其它字符 -> 跳过
105                 {
106                     vOtherStr = StringReducingOne(vOtherStr);
107                 }
108                 vRetStr = vOtherStr + (char)vIntChar;
109             }
110             return vRetStr;
111         }
112 
113         /// <summary>
114         /// 通过ASCII码值，对字符串自增
115         /// </summary>
116         /// <param name="pStr">输入字符串</param>
117         /// <param name="pCount">自增个数</param>
118         /// <returns></returns>
119         public static string StringIncrease(string pStr, int pCount)
120         {
121             string vRetStr = pStr;
122             for (int i = 0; i < pCount; i++)
123             {
124                 vRetStr = StringIncreaseOne(vRetStr);
125             }
126             return vRetStr;
127         }
128 
129         /// <summary>
130         /// 通过ASCII码值，对字符串自减
131         /// </summary>
132         /// <param name="pStr">输入字符串</param>
133         /// <param name="pCount">自减个数</param>
134         /// <returns></returns>
135         public static string StringReducing(string pStr, int pCount)
136         {
137             string vRetStr = pStr;
138             for (int i = 0; i < pCount; i++)
139             {
140                 vRetStr = StringReducingOne(vRetStr);
141             }            
142             return vRetStr;
143         }
144         
145 
146 
147     }