Using Eval to bind a dropdownlist

I have a dropdownlist that gets data through entity objects, but with a navigation. But I get an error trying to do this, can anyone help me please.

<asp:DropDownList ID="ddlVacancy" DataValueField="ID" DataTextField='<%# Eva开发者_如何学Gol("Position.Name") %>' runat="server" Width="200px"/>

You can create a property in your entity object like this:

        public string PositionName
        {
           get
           {
               return Position.Name;
           }
        }

and then replace Eval("Position.Name") with Eval("PositionName")

hope this helps

I had the same issue and I managed to create a simple control that derives from DropDownList. I also implemented an ItemDataBound Event that can help as well.

public class RTIDropDownList : DropDownList
{
    public delegate void ItemDataBoundDelegate( ListItem item, object dataRow );
    [Description( "ItemDataBound Event" )]
    public event ItemDataBoundDelegate ItemDataBound;

    protected override void PerformDataBinding( IEnumerable dataSource )
    {
        if ( dataSource != null )
        {
            if ( !AppendDataBoundItems )
                this.Items.Clear();

            IEnumerator e = dataSource.GetEnumerator();

            while ( e.MoveNext() )
            {
                object row = e.Current;

                var item = new ListItem( DataBinder.Eval( row, DataTextField, DataTextFormatString ).ToString(), DataBinder.Eval( row, DataValueField ).ToString() );

                this.Items.Add( item );

                if ( ItemDataBound != null ) // 
                    ItemDataBound( item, row );
            }
        }
    }
}