中英文混合字符串判定长度方法

protected void Button1_Click(object sender, EventArgs e)
    {
        int len = 0;
        string Text = TextBox1.Text;
        for (int i = 0; i < Text.Length; i++)
        {
            byte[] byte_len = Encoding.Default.GetBytes(Text.Substring(i, 1));
            if (byte_len.Length > 1)
                len += 2; //如果长度大于1，是中文，占两个字节，+2
            else
                len += 1;  //如果长度等于1，是英文，占一个字节，+1
        }
        Label1.Text = len.ToString();
    }