不区分中英文截断字符串

public static string GetString(this HtmlHelper htmlHelper, string s, int l, string endStr)

{

string temp = s.Substring(0, (s.Length < l + 1) ? s.Length : l + 1);

byte[] encodedBytes = Encoding.ASCII.GetBytes(temp);

string outputStr = string.Empty;

int count = 0;

for (int i = 0; i < temp.Length; i++)

{

if (encodedBytes[i] == 63)

{

count += 2;

}

else

{

count += 1;

}

if (count <= l - endStr.Length)

{

outputStr += temp.Substring(i, 1);

}

else if (count > l)

{

break;

}

}

if (count <= l)

{

outputStr = temp;

endStr = string.Empty;

}

outputStr += endStr;

return outputStr;

}