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Data Binding Overview

RadTreeView supports binding to various types of data sources:

In addition, while not strictly data binding, RadTreeView can load XML content files.

Databinding Properties and Methods

The following properties and methods are used when binding the RadTreeView to a data source:

  • DataSource property: Set to an instance of your data source. This is mandatory when binding the RadTreeView at runtime.

  • DataSourceID property: Set to the ID of your data source. This is mandatory when binding the RadTreeView declaratively.

  • DataMember property: If the data source is a DataSet and DataMember is set, then the RadTreeView is bound to the DataTable with the respective name in the DataSet. If DataMember is not set, the RadTreeView is bound to the first DataTable in the DataSet.

  • DataFieldID property: This is the field name from the data source used to uniquely identify each row. This field is required when binding to hierarchical data.

  • DataFieldParentID property: This is the field name from the data source used to identify the row for the parent node. This field is required when binding to hierarchical data.

  • DataTextField property: This is the field name from the data source that populates each Node's Text property during binding.

  • DataValueField property: This is the field name from the data source that populates each Node's Value property during binding.

  • DataNavigateUrlField property: This is the field name from the data source that populates each Node's NavigateUrlField property during binding.

  • DataBind method: Call this method after you have set the aforementioned properties when binding at runtime. This method is mandatory for binding at runtime.

note

If you need to map additional fields from the Data Source to properties of the RadTreeView Node, you can use the NodeDataBound event.

Appending Data Bound Items

RadTreeView exposes the AppendDataBoundItems property (False by default). If you bind the RadTreeView using the DataBind method, all RadTreeView Nodes are automatically cleared. Setting AppendDataBoundItems to True preserves the Nodes that are already present in the RadTreeView. This lets you bind RadTreeView to multiple data sources or use both unbound and bound modes.

Binding depth

RadTreeView exposes the MaxDataBindDepth property. This property is used to determine the binding depth. If for example you want to bind only the first two levels of the TreeView, you should set this property to 2. The default value of the MaxDataBindDepth property is -1, which means that all Nodes will be bound. Marking the TreeView instance with MaxDataBindDepth="0" will NOT bind any Nodes.

Using Templates with Data-bound Items

You can also use Templates with a data-bound RadTreeView. 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 the RadTreeView Node when it is in a bound mode. The RadTreeView item must already be bound before template binding can work.

For an live example of data-binding RadTreeView, see DataBinding.

See Also