RadioButtonList control problem

handi1111

When making a RadioButtonList control, when the AUTOPOSTBACK property is set to true, the selection returns to the default value.
  Data binding
RadioButtonList1.DataSource = DS.Tables [0] .DefaultView;
RadioButtonList1.DataTextField = "drug name"; RadioButtonList1.DataValueField = "drug name";
RadioButtonList1.DataBind ();
When ready to output to lable5 after selection
this.Label5.Text = RadioButtonList1.SelectedItem.Value;
Display error Object reference is not set to an instance of the object.

huilee

I also encountered this problem, I hope the master can solve it, I am a novice

xwgjyhl

Where are the binding events written?
! IsPostBack()

everever30

The binding is written in
if(!IsPostBack)
{
  bind your radiobuttonlist;
}