Caching Data used with a Combobox

[Michael]

I am using the following combobox to select cities from a view with 30000 rows.  

<telerik:RadComboBox ID="ddlCityO" TabIndex="1" runat="server" EmptyMessage="City, State" EnableItemCaching="True" DataSourceID="SqlDataSource1" MarkFirstMatch="True" EnableAutomaticLoadOnDemand="True" MinFilterLength="1" DataTextField="CityState" DataValueField="ID" DropDownAutoWidth="Enabled" Filter="Contains" Skin="MetroTouch" Placeholder="Destination" Width="300px"/>

Is there a better way to approach this?

I have tried to push the data into a datatable:

            db.Open()

            cmd = New SqlCommand("SELECT ID, CityState FROM v_City", db)
            cmd.CommandType = CommandType.Text



            Dim da As SqlDataAdapter = New SqlDataAdapter()
            da.SelectCommand = cmd


            Dim ds As New DataTable
            da.Fill(ds)
            db.Close()

            ddlCityO.DataSourceID = "datatable"
            ddlCityO.DataSource = ds
            ddlCityO.DataTextField = "CityState"
            ddlCityO.DataValueField = "ID"
            ddlCityO.DataBind()

 

This returns an error of "There is no assigned datasource. Unable to complete the callback request"

Any ideas?

[Peter Milchev]

Hello Michael,

When setting the DataSource property, the DataSourceId should not be set. 

Also, when using the DataSource property with the AutomaticLoadOnDemand, the DataSource should be set on every postback as suggested in the Automatic Load On Demand article.

Please find attached a sample project implementing the suggested approach.

Regards,
Peter Milchev
Progress Telerik