Populate DropDownList with Selected Value in Repeater using C# and VB.Net in ASP.Net

Hi makifkrpnr,

Check this example. Now please take its reference and correct your code.

HTML

<asp:Repeater ID="rptCustomers" runat="server" OnItemDataBound="rptCustomers_ItemDataBound">
    <ItemTemplate>
        <div>
            <label><%#Eval("Name") %></label>
            <asp:DropDownList ID="ddlCountries" runat="server">
            </asp:DropDownList>
        </div>
    </ItemTemplate>
</asp:Repeater>

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
                        new DataColumn("Name", typeof(string)),
                        new DataColumn("Country",typeof(string)) });
        dt.Rows.Add(1, "John Hammond", "United States");
        dt.Rows.Add(2, "Mudassar Khan", "India");
        dt.Rows.Add(3, "Suzanne Mathews", "France");
        dt.Rows.Add(4, "Robert Schidner", "Russia");
        rptCustomers.DataSource = dt;
        rptCustomers.DataBind();
    }
}

protected void rptCustomers_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    string id = Convert.ToString(DataBinder.Eval(e.Item.DataItem, "Id"));
    DropDownList ddlCountries = e.Item.FindControl("ddlCountries") as DropDownList;
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[2] { new DataColumn("Id", typeof(int)), new DataColumn("Country", typeof(string)) });
        dt.Rows.Add(1, "United States");
        dt.Rows.Add(2, "India");
        dt.Rows.Add(3, "France");
        ddlCountries.DataSource = dt;
        ddlCountries.DataTextField = "Country";
        ddlCountries.DataValueField = "Id";
        ddlCountries.DataBind();
        ddlCountries.Items.Insert(0, new ListItem { Text = "Select", Value = "0" });
        if (ddlCountries.Items.FindByValue(id) != null)
        {
            ddlCountries.Items.FindByValue(id).Selected = true;
        }
        else
        {
            ddlCountries.SelectedIndex = 0;
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    If Not Me.IsPostBack Then
        Dim dt As DataTable = New DataTable()
        dt.Columns.AddRange(New DataColumn(2) {
                            New DataColumn("Id", GetType(Integer)), New DataColumn("Name", GetType(String)), New DataColumn("Country", GetType(String))})
        dt.Rows.Add(1, "John Hammond", "United States")
        dt.Rows.Add(2, "Mudassar Khan", "India")
        dt.Rows.Add(3, "Suzanne Mathews", "France")
        dt.Rows.Add(4, "Robert Schidner", "Russia")
        rptCustomers.DataSource = dt
        rptCustomers.DataBind()
    End If
End Sub

Protected Sub rptCustomers_ItemDataBound(ByVal sender As Object, ByVal e As RepeaterItemEventArgs)
    Dim id As String = Convert.ToString(DataBinder.Eval(e.Item.DataItem, "Id"))
    Dim ddlCountries As DropDownList = TryCast(e.Item.FindControl("ddlCountries"), DropDownList)
    If e.Item.ItemType = ListItemType.Item OrElse e.Item.ItemType = ListItemType.AlternatingItem Then
        Dim dt As DataTable = New DataTable()
        dt.Columns.AddRange(New DataColumn(1) {
                            New DataColumn("Id", GetType(Integer)), New DataColumn("Country", GetType(String))})
        dt.Rows.Add(1, "United States")
        dt.Rows.Add(2, "India")
        dt.Rows.Add(3, "France")
        ddlCountries.DataSource = dt
        ddlCountries.DataTextField = "Country"
        ddlCountries.DataValueField = "Id"
        ddlCountries.DataBind()
        ddlCountries.Items.Insert(0, New ListItem With {.Text = "Select", .Value = "0"})
        If ddlCountries.Items.FindByValue(id) IsNot Nothing Then
            ddlCountries.Items.FindByValue(id).Selected = True
        Else
            ddlCountries.SelectedIndex = 0
        End If
    End If
End Sub

Screenshot