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;

sb.Append(Convert.ToString(Char));

if(i > len)

{

sb.Append(tag);

i = 0;

}

}

return sb.ToString();

}