字符串的截取（公共方法）

超、凢脫俗 2023-08-17 16:18 5阅读 0赞

1 #region 从字符串的指定位置截取指定长度的子字符串
     2         /// <summary>
     3         /// 从字符串的指定位置截取指定长度的子字符串
     4         /// </summary>
     5         /// <param name="str">原字符串</param>
     6         /// <param name="startIndex">子字符串的起始位置</param>
     7         /// <param name="length">子字符串的长度</param>
     8         /// <returns>子字符串</returns>
     9         private static string CutString(string str, int startIndex, int length)
    10         {
    11             if (startIndex >= 0)
    12             {
    13                 if (length < 0)
    14                 {
    15                     length = length * -1;
    16                     if (startIndex - length < 0)
    17                     {
    18                         length = startIndex;
    19                         startIndex = 0;
    20                     }
    21                     else
    22                     {
    23                         startIndex = startIndex - length;
    24                     }
    25                 }
    26 
    27                 if (startIndex > str.Length)
    28                 {
    29                     return "";
    30                 }
    31             }
    32             else
    33             {
    34                 if (length < 0)
    35                 {
    36                     return "";
    37                 }
    38                 else
    39                 {
    40                     if (length + startIndex > 0)
    41                     {
    42                         length = length + startIndex;
    43                         startIndex = 0;
    44                     }
    45                     else
    46                     {
    47                         return "";
    48                     }
    49                 }
    50             }
    51 
    52             if (str.Length - startIndex < length)
    53             {
    54                 length = str.Length - startIndex;
    55             }
    56 
    57             return str.Substring(startIndex, length);
    58         }
    59        
    60         /// <summary>
    61         /// 从字符串的指定位置开始截取到字符串结尾的了符串
    62         /// </summary>
    63         /// <param name="str">原字符串</param>
    64         /// <param name="startIndex">子字符串的起始位置</param>
    65         /// <returns>子字符串</returns>
    66         private static string CutString(string str, int startIndex)
    67         {
    68             return CutString(str, startIndex, str.Length);
    69         }
    70         #endregion

转载于:https://www.cnblogs.com/hugeboke/p/11574677.html