class StringOP     {         /// <summary>         /// 获取中英文混排字符串的实际长度(字节数)         /// </summary>         /// <param name="str">要获取长度的字符串</param>         /// <returns>字符串的实际长度值（字节数）</returns>         public int getStringLength(string str)         {             if (str.Equals(string.Empty))                 return 0;             int strlen = 0;             ASCIIEncoding strData = new ASCIIEncoding();             //将字符串转换为ASCII编码的字节数字             byte[] strBytes = strData.GetBytes(str);             for (int i = 0; i <= strBytes.Length - 1; i++)             {                 if (strBytes[i] == 63)  //中文都将编码为ASCII编码63,即"?"号                     strlen++;                 strlen++;             }             return strlen;         }     }     class TestMain     {         static void Main()         {             StringOP sop = new StringOP();             string str = "I Love China!I Love 北京！";             int iLen = sop.getStringLength(str);             Console.WriteLine("字符串" + str + "的字节数为：" + iLen.ToString());             Console.ReadKey();         }     }

public static int bytelenght(string str)         {             //使用Unicode编码的方式将字符串转换为字节数组,它将所有字符串(包括英文中文)全部以2个字节存储             byte[] bytestr = System.Text.Encoding.Unicode.GetBytes(str);             int j = 0;             for (int i = 0; i < bytestr.GetLength(0); i++)             {                 //取余2是因为字节数组中所有的双数下标的元素都是unicode字符的第一个字节                 if (i % 2 == 0)                 {                     j++;                 }                 else                 {                     //单数下标都是字符的第2个字节,如果一个字符第2个字节为0,则代表该Unicode字符是英文字符,否则为中文字符                     if (bytestr[i] > 0)                     {                         j++;                     }                 }             }             return j;         }

byte[] sarr = System.Text.Encoding.Default.GetBytes(s);    int len = sarr.Length;