RadCombobox fully supports binding to various data sources:
Data sources can support both hierarchical and non-hierarchical structures. RadComboBox, however, only works with a flat structure - items cannot contain children.
The following properties and methods are used when binding RadComboBox to a data source:
DataSource property - set to an instance of your data source. This is mandatory when binding RadComboBox at runtime.
DataSourceID property - set to the ID of your data source. This is mandatory when binding RadComboBox declaratively.
DataMember property - if the data source is a DataSet and DataMember is set, then RadComboBox is bound to the DataTable with the respective name in the DataSet. If DataMember is not set, RadComboBox is bound to the first DataTable in the DataSet.
DataTextField property - field name from the data source to bind to the Text property.
DataValueField property - field name from the data source to bind to the Value property.
DataBind method - must be called after the aforementioned properties are set, when binding at runtime. This method is mandatory for binding at runtime.
If you need to map additional fields from the Data Source to properties of RadComboBox item, the ItemDataBound event should be used. See Binding To ASP DataSource Components, for an example.
RadComboBox exposes the AppendDataBoundItems property (set to False by default). If you bind the RadComboBox using the DataBind method, all RadComboBox items are automatically cleared.
Setting AppendDataBoundItems to True preserves the items that are already present in RadComboBox. This lets you bind RadComboBox to multiple data sources or use both unbound and bound modes.
You can also use templates with a data bound RadComboBox. To bind template items to column values, use DataBinder.Eval expressions in the template's definition:
<%# DataBinder.Eval(Container.DataItem, "ColumnName") %>
Note that you use Container.DataItem to access RadComboBox item when it is in bound mode. The RadComboBox item must already be bound before template binding can work.
For an live example of data-binding RadComboBox, see DataBinding online demo.
See Custom Attributes -> Using custom attributes in server-side code -> Data binding RadComboBox for more information.