Binding to XML
To bind the RadTreeView to a XML you will need to convert the XML to a collection and then to bind that collection using the ItemsSource property of the RadTreeView. This tutorial will show you how to do this.
The final result should look like the snapshot below:
- The first step is to add references to the following assemblies:
- Telerik.Windows.Controls.Navigation
- Telerik.Windows.Controls
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Then add the xml file describing the data that will be displayed in the RadTreeView control. Below you can find a simple XML declaration, that we will use in this tutorial:
<?xml version="1.0" encoding="UTF-8"?> <Items> <XmlNodeItem Header="Animal"> <Items> <XmlNodeItem Header="Dog" /> <XmlNodeItem Header="Cat" /> </Items> </XmlNodeItem> <XmlNodeItem Header="Fish"> <Items> <XmlNodeItem Header="Fresh Water"> <Items> <XmlNodeItem Header="Roach"/> <XmlNodeItem Header="Bream"/> </Items> </XmlNodeItem> <XmlNodeItem Header="Salt Water"> <Items> <XmlNodeItem Header="Edible"/> <XmlNodeItem Header="Flat"> <Items> <XmlNodeItem Header="Skate"/> <XmlNodeItem Header="Soul"/> </Items> </XmlNodeItem> </Items> </XmlNodeItem> </Items> </XmlNodeItem> </Items> -
Create a new class named XmlNodeItem. The class is pretty simple and it represents a separate node from the XML document. It has a Header property and a collection of XmlNodeItem. Here is the source code:
public class XmlNodeItem { public XmlNodeItem() { this.Items = new ObservableCollection<XmlNodeItem>(); } [XmlAttribute( AttributeName = "Header" )] public string Header { get; set; } public ObservableCollection<XmlNodeItem> Items { get; set; } }Public Class XmlNodeItem Public Sub New() Me.Items = New ObservableCollection(Of XmlNodeItem)() End Sub Private _Header As String <XmlAttribute(AttributeName = "Header")> _ Public Property Header() As String Get Return _Header End Get Set(ByVal value As String) _Header = value End Set End Property Private _Items As ObservableCollection(Of XmlNodeItem) Public Property Items() As ObservableCollection(Of XmlNodeItem) Get Return _Items End Get Set(ByVal value As ObservableCollection(Of XmlNodeItem)) _Items = value End Set End Property End Class -
Create a new class named XmlNodeItemList, which derives from ObservableCollection of XmlNodeItem. This is a collection that will be created from the XML file. The RadTreeView will be bound to this collection.
[XmlRoot( ElementName = "Items" )] public class XmlNodeItemList : ObservableCollection<XmlNodeItem> { public void AddRange( IEnumerable<XmlNodeItem> range ) { foreach ( XmlNodeItem node in range ) { this.Add( node ); } } }<XmlRoot(ElementName = "Items")> _ Public Class XmlNodeItemList Inherits ObservableCollection(Of XmlNodeItem) Public Sub AddRange(ByVal range As IEnumerable(Of XmlNodeItem)) For Each node As XmlNodeItem In range Me.Add(node) Next End Sub End Class -
Create a new class named RadTreeViewXmlDataSource, which derives from XmlNodeItemList. Practically, this will be the data source (the model) for the treeview. The class takes a path to the XML file and deserialize the data in the private method RetrieveData.
public class RadTreeViewXmlDataSource : XmlNodeItemList { private string source; public string Source { get { return this.source; } set { this.source = value; AddRange( RetrieveData( Application.GetResourceStream( new Uri( value, UriKind.Relative ) ).Stream ) ); } } private XmlNodeItemList RetrieveData( Stream xmlStream ) { XmlSerializer serializer = new XmlSerializer( typeof( XmlNodeItemList ) ); StreamReader reader = new StreamReader( xmlStream ); XmlNodeItemList list = ( XmlNodeItemList )serializer.Deserialize( reader ); return list; } }Public Class RadTreeViewXmlDataSource Inherits XmlNodeItemList Private m_source As String Public Property Source() As String Get Return Me.m_source End Get Set(ByVal value As String) Me.m_source = value AddRange(RetrieveData(Application.GetResourceStream(New Uri(value, UriKind.Relative)).Stream)) End Set End Property Private Function RetrieveData(ByVal xmlStream As Stream) As XmlNodeItemList Dim serializer As New XmlSerializer(GetType(XmlNodeItemList)) Dim reader As New StreamReader(xmlStream) Dim list As XmlNodeItemList = DirectCast(serializer.Deserialize(reader), XmlNodeItemList) Return list End Function End Class -
The next step is to declare the RadTreeViewXmlDataSource as a resource in your application.
<UserControl.Resources> <example:RadTreeViewXmlDataSource x:Key="treeViewData" Source="RadTreeViewBindingToXml.xml"/> <!--Create HierarchicalDataTemplate--> </UserControl.Resources>The example alias points to the local namespace used in your project.
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Since the data is hierarchical, you need to declare a HierarchicalDataTemplate. If you want to learn about the hierarchical data template, read the topic about Hierarchical Data Templates.
<UserControl.Resources> <example:RadTreeViewXmlDataSource x:Key="treeViewData" Source="RadTreeViewBindingToXml.xml"/> <HierarchicalDataTemplate x:Key="Item" ItemsSource="{Binding Items}"> <TextBlock Text="{Binding Header}" /> </HierarchicalDataTemplate> </UserControl.Resources> -
Finally, here is the treeview declaration. For ItemsSource is used the treeViewData resource. For ItemTemplate is set the created in the previous step hierarchical data template.
<telerik:RadTreeView ItemTemplate="{StaticResource Item}" ItemsSource="{Binding Source={StaticResource treeViewData}}"/> Here is the final result.
