public static string FormatStr(string str, int len, string tag)

              {

                     char[] arrChar = new char[10]{ '。','，','~','！','、','？','*','…','￥','$'};

                     StringBuilder sb = new StringBuilder();

                     int i = 0;

                     foreach (char Char in str)

                     {

                            bool bIsContain = false;

                            for(int j = 0; j < arrChar.Length; j++)

                            {

                                   if(Char.CompareTo(arrChar[j]) == 0)

                                   {

                                          bIsContain = true;

                                          break;

                                   }

                            }

                            if ((int)Char <= 127 || bIsContain)

                                   i += 1;

                            else

                                   i = 0;

       &nb