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Binding to RadClientDataSource

This article demonstrates how to bind RadListBox to RadClientDataSource.

Since Q2 2014 RadListBox can be bound to a RadClientDataSource control. An important aspect of binding to the RadClientDataSource is that the RadListBox DataKeyField, DataText and DataValue fields should be associated with the custom object properties. Thus you can choose which property value to be shown as RadListBox item text and value. For reference at the bottom of the web service implementation below you will find the custom class and its properties declaration.

The following application scenario shows an example of such scenario.

When the LoadOnDemand functionality is enabled RadListBox requests items from the RadClientDataSource on portions.In case that this functionality is disabled the items are request at once.

<telerik:RadClientDataSource runat="server" ID="CD1">
    <ClientEvents />
        <WebServiceDataSourceSettings BaseUrl="http://url/Service.svc/">
            <Select Url="LoadCustomDataWCF" DataType="JSON" RequestType="Post" ContentType="application/json; charset=utf-8" />
    <Schema DataName="d">
    <ClientEvents />
<br />
<telerik:RadListBox RenderMode="Lightweight" Height="100px" TabIndex="1" runat="server" ID="ListBox1" ClientDataSourceID="CD1"
    DataTextField="Name" DataValueField="Value" EnableLoadOnDemand="true">
public CustomData[] LoadCustomDataWCF()
    NorthwindReadOnlyDataContext northwind = new NorthwindReadOnlyDataContext();

    //Get all items from the Customers table. This query will not be executed untill the ToArray method is called.
    var allCustomers = (from customer in northwind.Customers
                        orderby customer.ContactName
                        select new CustomData
                            Name = customer.ContactName,
                            Value = customer.CustomerID

    var result = allCustomers.ToArray();

    return result;

public class CustomData
    public string Name { get; set; }
    public string Value { get; set; }

Inherits System.Web.UI.Page
<OperationContract> _
Public Function LoadCustomDataWCF() As CustomData()
    Dim northwind As New NorthwindReadOnlyDataContext()

    'Get all items from the Customers table. This query will not be executed untill the ToArray method is called.
Dim allCustomers = (From customer In northwind.CustomersOrder By customer.ContactNameNew CustomData() With { _
    Key .Name = customer.ContactName, _
    Key .Value = customer.CustomerID _
}).Take(Of CustomData)(46)

    Dim result = allCustomers.ToArray()

    Return result
End Function

Public Class CustomData
    Public Property Name() As String
            Return m_Name
        End Get
        Set(value As String)
            m_Name = Value
        End Set
    End Property
    Private m_Name As String
    Public Property Value() As String
            Return m_Value
        End Get
        Set(value As String)
            m_Value = Value
        End Set
    End Property
    Private m_Value As String

End Class
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