how to add data in dropdownlist inside repeator in asp.net

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
LoadDropDown1();
LoadRepeater();
}
}

private void LoadRepeater()
{
List<int> items = new List<int>() { 1, 2, 3, 4, 5 };
Repeater1.DataSource = items;
Repeater1.DataBind();
}

private void LoadDropDown1()
{
Dictionary<int,> listOfData = new Dictionary<int,>();
listOfData.Add(1, "Item1");
listOfData.Add(2, "Item2");
listOfData.Add(3, "Item3");
listOfData.Add(4, "Item4");

FillDropDownList(ref ddl1, listOfData);
}

private void FillDropDownList(ref DropDownList ddl, Dictionary<int,> data)
{
ddl.DataSource = data;
ddl.DataTextField = "Value";
ddl.DataValueField = "Key";
ddl.DataBind();
}

protected void ddl1_SelectedIndexChanged(object sender, EventArgs e)
{
LoadRepeater();
}

protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
DropDownList ddl2 = e.Item.FindControl("ddl2") as DropDownList;

Dictionary<int,> listOfData = new Dictionary<int,>();
listOfData.Add(1, "Item1");
listOfData.Add(2, "Item2");
listOfData.Add(3, "Item3");
listOfData.Add(4, "Item4");

FillDropDownList(ref ddl2, listOfData);
}
}