txtResult.Text = "";
            string value = txtValues.Text.Trim();
            if (string.IsNullOrEmpty(value))
            {
                return;
            }
            StringBuilder sb = new StringBuilder();
            byte[] by = Encoding.Unicode.GetBytes(value);
            foreach (var item in by)
            {
                sb.Append(Convert.ToString(item,int.Parse(drValue.SelectedValue.ToString())));
            }
            txtResult.Text = sb.ToString();

var sp=38;
sp.toString(2);