DetailsView FindControl when Edit or Insert mode

Must in the PreRender or ItemCreated even.

.aspx file:

onprerender="DetailsView1_PreRender"

.cs file:

protected void DetailsView1_PreRender(object sender, EventArgs e)

    {

        if (IsPostBack)

        {

            DetailsView detailsView = (DetailsView)sender;

            if (detailsView.CurrentMode == DetailsViewMode.Edit)

            {

                DropDownList dropDownList = (DropDownList)detailsView.FindControl("DropDownList1");

                dropDownList.Items.Add(new ListItem("text", "value"));

            }

        }

    }