下拉列表计算中的选项

string IsChauffeurUsed = "Yes";
    totalValue += IsChauffeurUsed.Equals("Yes", StringComparison.CurrentCultureIgnoreCase) ? 80 : 0;
    Label8.Text = totalValue.ToString();

上面的代码行使系统加80加后

计算

 int totalValue = 0;
    totalValue = int.Parse(Session["price"].ToString()) * int.Parse(Session["day"].ToString());

如何使其仅添加80，如果只有用户在下拉列表中选择"是"。我将选择存储在会话中

Session["IsChauffeurUsed"] = DropDownList4.SelectedItem.Text;

string IsChauffeurUsed = Session["IsChauffeurUsed"].ToString();
totalValue += IsChauffeurUsed.Equals("Yes", StringComparison.CurrentCultureIgnoreCase) ? 80 : 0;

string IsChauffeurUsed = CB.SelectedItem.ToString();
if (IsChauffeurUsed == "Yes")
{
  //Do condition calculations here
}