Selecting Treeviewitem in WPF - wpf-controls

Question

I have a search textbox to search the treeviewitem and select it. The child items in treeview are lazy loaded.
I want to select the child times of a treeview passed in search textbox.
how can i achieve this?
Thanks
Sharath

Answer 1

There's some good information about selecting items in a TreeView here:
http://askernest.com/archive/2008/01/23/how-to-programmatically-change-the-selecteditem-in-a-wpf-treeview.aspx
and here:
http://www.codeproject.com/KB/WPF/TreeView_SelectionWPF.aspx

Answer 2

Here is my helper, extract what you need:
PS. I never tested the ExpandAll method.
Imports System.Runtime.CompilerServices
Imports System.Windows.Controls.Primitives
<HideModuleName()>
Module TreeViewHelper
<Extension()>
Public Sub SetSelectedItem(ByVal treeView As TreeView, ByVal item As Object)
SetSelectedItemInternal(treeView, item)
End Sub
<Extension()>
Public Sub SetSelectedItem(ByVal treeViewItem As TreeViewItem,
ByVal item As Object)
SetSelectedItemInternal(treeViewItem, item)
End Sub
Private Sub SetSelectedItemInternal(ByVal control As ItemsControl,
ByVal item As Object)
ValidateItemsControl(control)
If item Is Nothing Then Throw New ArgumentNullException("item")
If Not control.Items.Contains(item) Then _
Throw New ArgumentOutOfRangeException("item",
"Specified item was not found in the control.")
If control.ItemContainerGenerator.Status =
GeneratorStatus.ContainersGenerated Then
DirectCast(control.ItemContainerGenerator.ContainerFromItem(item),
TreeViewItem).IsSelected = True
Else
Dim selectWhenReadyMethod As EventHandler
selectWhenReadyMethod =
Sub(sender, e)
If control.ItemContainerGenerator.Status =
GeneratorStatus.ContainersGenerated Then
RemoveHandler control.ItemContainerGenerator.StatusChanged,
selectWhenReadyMethod
SetSelectedItemInternal(control, item)
End If
End Sub
AddHandler control.ItemContainerGenerator.StatusChanged,
selectWhenReadyMethod
End If
End Sub
<Extension()>
Public Sub SetSelectedIndex(ByVal treeView As TreeView, ByVal index As Object)
SetSelectedIndexInternal(treeView, index)
End Sub
<Extension()>
Public Sub SetSelectedIndex(ByVal treeViewItem As TreeViewItem,
ByVal index As Object)
SetSelectedIndexInternal(treeViewItem, index)
End Sub
Private Sub SetSelectedIndexInternal(ByVal control As ItemsControl,
ByVal index As Object)
ValidateItemsControl(control)
If index < 0 OrElse index > control.Items.Count - 1 Then _
Throw New ArgumentOutOfRangeException("index")
If control.ItemContainerGenerator.Status =
GeneratorStatus.ContainersGenerated Then
DirectCast(control.ItemContainerGenerator.ContainerFromIndex(index),
TreeViewItem).IsSelected = True
Else
Dim selectWhenReadyMethod As EventHandler
selectWhenReadyMethod =
Sub(sender, e)
If control.ItemContainerGenerator.Status =
GeneratorStatus.ContainersGenerated Then
RemoveHandler control.ItemContainerGenerator.StatusChanged,
selectWhenReadyMethod
SetSelectedIndexInternal(control, index)
End If
End Sub
AddHandler control.ItemContainerGenerator.StatusChanged,
selectWhenReadyMethod
End If
End Sub
<Extension()>
Public Sub ExpandAll(ByVal treeView As TreeView)
ExpandAllInternal(treeView)
End Sub
<Extension()>
Public Sub ExpandAll(ByVal treeViewItem As TreeViewItem)
ExpandAllInternal(treeViewItem)
End Sub
Private Sub ExpandAllInternal(ByVal control As ItemsControl)
ValidateItemsControl(control)
If control.Items.IsEmpty Then Exit Sub
If control.ItemContainerGenerator.Status =
GeneratorStatus.ContainersGenerated Then
For i = 0 To control.Items.Count - 1
Dim item =
DirectCast(control.ItemContainerGenerator.ContainerFromIndex(i),
TreeViewItem)
item.IsExpanded = True
ExpandAllInternal(control)
Next
Else
Dim expandWhenReadyMethod As EventHandler
expandWhenReadyMethod =
Sub(sender, e)
If control.ItemContainerGenerator.Status =
GeneratorStatus.ContainersGenerated Then
RemoveHandler control.ItemContainerGenerator.StatusChanged,
expandWhenReadyMethod
ExpandAllInternal(control)
End If
End Sub
AddHandler control.ItemContainerGenerator.StatusChanged,
expandWhenReadyMethod
End If
End Sub
Private Sub ValidateItemsControl(ByVal control As ItemsControl)
If control Is Nothing Then Throw New ArgumentNullException("control")
If Not TypeOf control Is TreeView AndAlso
Not TypeOf control Is TreeViewItem Then _
Throw New _
NotSupportedException(control.GetType.FullName & " is not supported.")
End Sub
End Module