写法有很多，记录常用的两种：

1、正则表达式

1          public static string MidStrEx_New(string sourse, string startstr, string endstr)2         {3             Regex rg = new Regex("(?<=(" + startstr + "))[.\\s\\S]*?(?=(" + endstr + "))", RegexOptions.Multiline | RegexOptions.Singleline);4             return rg.Match(sourse).Value;5         }

 

 

2、利用字符串indexof截取：

1         public static string MidStrEx(string sourse, string startstr, string endstr) 2         { 3             string result = string.Empty; 4             int startindex, endindex; 5             try 6             { 7                 startindex = sourse.IndexOf(startstr); 8                 if (startindex == -1) 9                     return result;10                 string tmpstr = sourse.Substring(startindex + startstr.Length);11                 endindex = tmpstr.IndexOf(endstr);           12                 if (endindex == -1)13                     return result;14                 result = tmpstr.Remove(endindex);15             }16             catch (Exception ex)17             {18                 Log.WriteLog("MidStrEx Err:" + ex.Message);19             }20             return result;21         }

就效率来说，测试了几次，方法2比方法1大约快10倍