# Data Binding Overview

**RadTreeView** supports binding to various types of data sources:

* [OData](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/binding-to-odata)

* [DataTable, DataSet, DataView](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/binding-to-datatable)

* [ASP 2.0 DataSource types](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/binding-to-asp.net-datasource-components)

* [Array, ArrayList, Generic Lists](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/binding-to-array-and-arraylist)

In addition, while not strictly data binding, **RadTreeView** can [load XML content](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/loading-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](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/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](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/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](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/data-binding/using-additional-columns).

## 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](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/templates/overview) with a data-bound **RadTreeView**. To bind template items to column values, use **DataBinder.Eval** expressions in the Template's definition:

```ASPNET
<%# 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](https://demos.telerik.com/aspnet-ajax/TreeView/Examples/Programming/DataBinding/DefaultCS.aspx).

## See Also

* [Binding to a Database](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/getting-started/binding-to-a-database)