User2103319870 posted
Hi,
Ensure that you are not populating the dropdownlist on every postback.
If you are binding the dropdown on postback try to wrap the databinding code inside a !IsPostback section like given below
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
//code to bind dropdown
}
}
One more suggestion is if you are using an update panel your dropdownlist should be present within that panel. This is because Selected value will only be available at the sever if the the page containing the dropdownlist
control is posted back.