Bind Data from drop down and listbox to Label

For ListBox:
 Label2.Text = ListBox1.SelectedValue.ToString();

For DropDownList :
 Label2.Text = DropDownList1.SelectedValue.ToString();

and select the autopostBack property true of Both      

First set autopostback=true on.your listbox or dropdown and on selectedindex change event write
Label1.text=dropdown.selecteditem.text;