dropdownlist1.selected.value的值应该如何转换成double类型那

dropdownlist1.selected.value的值应该怎么转换成double类型那?
dropdownlist1的选值想进行数学运算!

textbox组件可以用double   text1=double.Parse(TextBox1.Text);   转换为浮点!

那么dropdownlist应该怎样转换那?分很少,帮想想~

------解决方案--------------------------------------------------------
double selectValue =double.Parse(dropdownlist1.SelectValue);
------解决方案--------------------------------------------------------
Convert.ToDouble(dropdownlist1.selected.value.ToString())
------解决方案--------------------------------------------------------
都被说了，只能帮你顶一下了
------解决方案--------------------------------------------------------
jf
------解决方案--------------------------------------------------------
double.Parse(dropdownlist1.SelectValue.ToString())
Convert.ToDouble(dropdownlist1.selected.value.ToString())

这两个都可以的
------解决方案--------------------------------------------------------
double selectValue = Double.Parse(DropDownList1.SelectedValue);

or

double selectValue = Convert.ToDouble(DropDownList1.SelectedValue);