SelectedValue of DropDownList in Repeater

Question

How do I set the selected item of a dropDownList inside a repeater?

The repeater is bound to the repeaterData DataTable and the dropDownList is bound to dropDownList DataTable in the code behind. I need to set the SelectedValue property of the DropDownList to the value of a field from the repeaterData table.

This is what I've tried:

<asp:Repeater runat="server" ID="myRepeater>
<ItemTemplate>
    <asp:DropDownList runat="server" CssClass="fullSelect" ID="degree_dropdown"
            AppendDataBoundItems="true" 
            selectedValue='<%#DataBinder.Eval(Container.DataItem,"degreeCode")%>'>
                  <asp:ListItem Text="Select Degree" />
     </asp:DropDownList>
</ItemTemplate>
</asp:Repeater>

Code to populate repeater:

myRepeater.DataSource = myRepeaterData; //myRepeaterData is a datatable
myRepeater.DataBind();

Code to populate dropdownlist:

protected void educationPopup_repeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
        {
            DropDownList degree_dropdown = e.Item.FindControl("degree_dropdown") as DropDownList;
            if (degree_dropdown != null)
            {
                degree_dropdown.DataSource = degrees; //a datatable
                degree_dropdown.DataTextField = "degree";
                degree_dropdown.DataValueField = "code";
                degree_dropdown.DataBind();
            }
}

Frenchy

What event or method do you use to populate degree_dropdown with data? Could you post the code? – Empathy

Answer 1

You are almost there. You just need to cast DataItem to DataRowView, and assign it to DropDownList like this -

protected void myRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || 
       e.Item.ItemType == ListItemType.AlternatingItem)
    {
        var degree_dropdown = e.Item.FindControl("degree_dropdown") as DropDownList;
        string degreeCode = (string) ((DataRowView) e.Item.DataItem)["degreeCode"];

        if (degree_dropdown != null)
        {
            degree_dropdown.DataSource = degrees; //a datatable
            degree_dropdown.DataTextField = "degree";
            degree_dropdown.DataValueField = "code";
            degree_dropdown.DataBind();

            if (degree_dropdown.Items.FindByValue(degreeCode) != null)
                degree_dropdown.SelectedValue = degreeCode;
        }
    }
}

Empathy

Answer 2

With HTML5 custom attributes, you can set your dropdown value into a data attribute, and then setting it as selected value after the dropdown is databinded. I have binded the dropdown using asp:ObjectDataSource

<asp:Repeater runat="server" ID="myRepeater>
<ItemTemplate>

<asp:DropDownList runat="server" CssClass="fullSelect" ID="degree_dropdown"
            AppendDataBoundItems="true" 
            SetValue='<%#DataBinder.Eval(Container.DataItem,"degreeCode")%>'
datasourceid="dsCategory" datatextfield="degree" datavaluefield="code" onprerender="DropDownDataBinding">
                  <asp:ListItem Text="Select Degree" />
     </asp:DropDownList>
<asp:ObjectDataSource ID="dsCategory" runat="server" SelectMethod="LoadDegree" TypeName="WebApplication.WebForm1" />
</ItemTemplate>
</asp:Repeater>

CodeBehind

protected void DropDownDataBinding(object sender, EventArgs e) //Method to set the selected value on Category dropdown inside repeater
{
    DropDownList sel = (DropDownList)sender;
    sel.Value = sel.Attributes["SetValue"];
    ListItem li = new ListItem("<< Select >>", "");
    sel.Items.Insert(0,li);
}

protected DataTable LoadDegree()
{
        DataTable dt = new DataTable();
        dt = degrees; //a datatable
        return dt;

}

The binding of your repeater control will remain the same

Sudra