ASP.NET DropDownList SelectedValue property not set immediately

Question

I have an ASP.NET web form on which I use the DropDownList control so that the user can select the item and see the related results. For some reason, when I set the SelectedValue property to DropDownList, the value it set is not immediately available.

Here is my code:

protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        DropDownList1.SelectedValue = "5";
        BindView();
    }
}

protected void BindActivities()
{
    DataClassesDataContext dc = new DataClassesDataContext();
    var query = from activity in dc.Activities
                where activity.AssignedTo == Convert.ToInt32(DropDownList1.SelectedValue);
    GridView1.DataSource = query;
    GridView1.DataBind();
}

, DropDownList1.SelectedValue NULL. , , DropDownList1.SelectedValue , DropDownList1 5. , , , . , DropDownList.SelectedValue 5 , .

, ?

Answer 1

, ?

Answer 2

, .

if (!Page.IsPostBack)
{
    BindView();
    DropDownList1.SelectedValue = "5";
}

... .

, , .