Binding to ASP DataSource components
RadComboBox supports binding to all ASP.NET 2.0 DataSource components, including:
AccessDataSource
SqlDataSource
XmlDataSource
ObjectDataSource
SiteMapDataSource
LinqDataSource
To bind to a DataSource component, all you need to do is set the DataSourceID property of RadComboBox to the ID of the DataSource component. You should also set the DataTextField and DataValueField properties of RadComboBox to map the Text and Value properties of the items to the respective columns / fields from the data source.
If you need to map additional columns from the data source to properties of RadComboBox items, you can use the ItemDataBound event. The event arguments passed to the event, e.Item and e.Item.DataItem, hold the instance of RadComboBox item being bound and the DataItem to which it is bound. You can map a property from the DataItem to the corresponding property of RadComboBox item. Be sure to cast the DataItem object to the proper data type first.
protected void RadComboBox1_ItemDataBound(object o, RadComboBoxItemEventArgs e)
{
DataRowView dataSourceRow = (DataRowView)e.Item.DataItem;
e.Item.Enabled = (bool)dataSourceRow["Enabled"];
e.Item.Attributes["customAttribute"] = dataSourceRow["CustomAttribute"].ToString();
}
Protected Sub RadComboBox1_ItemDataBound(ByVal o As Object, ByVal e As
RadComboBoxItemEventArgs) Handles RadComboBox1.ItemDataBound
Dim dataSourceRow As DataRowView = DirectCast(e.Item.DataItem, DataRowView)
e.Item.Enabled = DirectCast(dataSourceRow("Enabled"), Boolean)
e.Item.Attributes("customAttribute") = dataSourceRow("CustomAttribute").ToString()
End Sub
AccessDataSource
<asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/Data/Combo.mdb"
SelectCommand="SELECT * FROM [Links]">
</asp:AccessDataSource>
<telerik:radcombobox
id="RadComboBox2"
runat="server"
datatextfield="Text"
datavaluefield="Value"
datasourceid="AccessDataSource1"
onitemdatabound="RadComboBox2_ItemDataBound" />
SqlDataSource
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ComboConnectionString %>"
SelectCommand="SELECT * FROM [Links]"></asp:SqlDataSource>
<telerik:radcombobox
id="RadComboBox1"
runat="server"
datatextfield="Text"
datavaluefield="Value"
datasourceid="SqlDataSource1"
onitemdatabound="RadComboBox1_ItemDataBound" />
XmlDataSource
<telerik:radcombobox
id="RadComboBox1"
runat="server"
datasourceid="XmlDataSource1"
datatextfield="Text"
datavaluefield="Value">
</telerik:radcombobox>
<asp:XmlDataSource ID="XmlDataSource1" runat="server" DataFile="~/ContentFile.xml"></asp:XmlDataSource>
When using an XmlDataSource, the XML file should have the format shown below:
<items>
<Item Text="New York" Value="1" />
<Item Text="Paris" Value="2" />
<Item Text="London" Value="3" />
</items>
You can also load the XML file directly, rather than using a DataSource component as an intermediary.
ObjectDataSource
<telerik:radcombobox
id="RadComboBox1"
runat="server"
datavaluefield="ID"
datatextfield="Text"
datasourceid="ObjectDataSource1">
</telerik:radcombobox>
<asp:ObjectDataSource ID="ObjectDataSource1" TypeName="ComboObjectData" SelectMethod="GetItems"
runat="server"></asp:ObjectDataSource>
public class ComboObjectData
{
public ComboObjectData() { }
public static List<ComboDataItem> GetItems()
{
List<ComboDataItem> itemsList = new List<ComboDataItem>();
itemsList.Add(new ComboDataItem(1, "item 1"));
itemsList.Add(new ComboDataItem(2, "item 2"));
itemsList.Add(new ComboDataItem(3, "item 3"));
return itemsList;
}
public class ComboDataItem
{
private string _text;
private int _id;
public string Text
{
get
{
return _text;
}
set
{
_text = value;
}
}
public int ID
{
get
{
return _id;
}
set
{
_id = value;
}
}
public ComboDataItem(int id, string text)
{
_id = id;
_text = text;
}
}
}
Public Class ComboObjectData
Public Sub New()
End Sub
Public Shared Function GetItems() As List(Of ComboDataItem)
Dim itemsList As New List(Of ComboDataItem)()
itemsList.Add(New ComboDataItem(1, "item 1"))
itemsList.Add(New ComboDataItem(2, "item 2"))
itemsList.Add(New ComboDataItem(3, "item 3"))
Return itemsList
End Function
Public Class ComboDataItem
Private _text As String
Private _id As Integer
Public Property Text() As String
Get
Return _text
End Get
Set(ByVal value As String)
_text = value
End Set
End Property
Public Property ID() As Integer
Get
Return _id
End Get
Set(ByVal value As Integer)
_id = value
End Set
End Property
Public Sub New(ByVal id As Integer, ByVal text As String)
_id = id
_text = text
End Sub
End Class
End Class