WPF TreeView Update

Question

I have a problem. I am using TreeView in my WPF project to render my XML data. The problem is that when I edit my XmlDocument , it does not update in TreeView . But I noticed that when I check SelectedNode , this is my edit and XmlNode . Therefore, my “Edit” method works fine, but there is only a problem in visually updating my tree. .Refresh() or .Items.Refresh() do not work either.

Here is the pattern of my tree:

 <DataTemplate x:Key="AttributeTemplate"> <StackPanel Orientation="Horizontal" Margin="3,0,0,0" HorizontalAlignment="Center"> <TextBlock Text="{Binding Path=Name}" Foreground="{StaticResource xmAttributeBrush}" FontFamily="Consolas" FontSize="8pt" /> <TextBlock Text="=&quot;" Foreground="{StaticResource xmlMarkBrush}" FontFamily="Consolas" FontSize="8pt" /> <TextBlock Text="{Binding Path=Value, Mode=TwoWay}" Foreground="{StaticResource xmlValueBrush}" FontFamily="Consolas" FontSize="8pt" /> <TextBlock Text="&quot;" Foreground="{StaticResource xmlMarkBrush}" FontFamily="Consolas" FontSize="8pt" /> </StackPanel> </DataTemplate> <HierarchicalDataTemplate x:Key="NodeTemplate"> <StackPanel Orientation="Horizontal" Focusable="False"> <TextBlock x:Name="tbName" Text="?" FontFamily="Consolas" FontSize="8pt" /> <ItemsControl ItemTemplate="{StaticResource AttributeTemplate}" ItemsSource="{Binding Path=Attributes}" HorizontalAlignment="Center"> <ItemsControl.ItemsPanel> <ItemsPanelTemplate> <StackPanel Orientation="Horizontal"/> </ItemsPanelTemplate> </ItemsControl.ItemsPanel> </ItemsControl> </StackPanel> <HierarchicalDataTemplate.ItemsSource> <Binding XPath="*" /> </HierarchicalDataTemplate.ItemsSource> <HierarchicalDataTemplate.Triggers> <DataTrigger Binding="{Binding Path=NodeType}" Value="Text"> <Setter TargetName="tbName" Property="Text" Value="{Binding Path=Value, Mode=TwoWay}"/> </DataTrigger> <DataTrigger Binding="{Binding Path=NodeType}" Value="Element"> <Setter TargetName="tbName" Property="Text" Value="{Binding Path=Name}"/> </DataTrigger> </HierarchicalDataTemplate.Triggers> </HierarchicalDataTemplate> <Style x:Key="TreeViewAllExpandedStyle" TargetType="{x:Type TreeView}"> <Style.Resources> <Style TargetType="TreeViewItem"> <Setter Property="IsExpanded" Value="True" /> </Style> </Style.Resources> </Style> <Style x:Key="TreeViewAllCollapsedStyle" TargetType="{x:Type TreeView}"> <Style.Resources> <Style TargetType="TreeViewItem"> <Setter Property="IsExpanded" Value="False" /> </Style> </Style.Resources> </Style> 

Here is Window.Resources :

 <Window.Resources> <XmlDataProvider x:Key="XmlData" /> </Window.Resources> 

Here is my tree:

 <TreeView x:Name="XmlTree" Grid.Row="1" ItemsSource="{Binding Source={StaticResource XmlData}, XPath=., Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" ItemTemplate="{StaticResource NodeTemplate}" SelectedItemChanged="XmlTree_SelectedItemChanged" /> 

And here is my code behind:

 private XmlDocument _xml; private XmlElement _selectedElement; private XmlDataProvider _xmlDataProvider; private void MainWindow_Load(object sender, EventArgs e) { XmlTree.Style = (Style)FindResource("TreeViewAllExpandedStyle"); _xmlDataProvider = FindResource("XmlData") as XmlDataProvider; } private void OpenXmlFile(string filePath) { _xml = new XmlDocument(); _xml.Load(filePath); _xmlDataProvider.Document = _xml; } private void SaveChangesButton_Click(object sender, EventArgs e) { Dictionary<string, string> newAttributes = GetChangedAttributes(); foreach (KeyValuePair<string, string> pair in newAttributes) { _selectedElement.SetAttribute(pair.Key, pair.Value); } RefreshViews(); } private void RefreshViews() { // now I don't know what to do here, any Refresh doesn't work:S } 

Secondly, how to clear my tree so that I can use it again for other data (I have a NullReferenceException when trying XmlTree.Items.Clear();

Answer 1

A few hours later, finally found a solution!

 private void RefreshViews() { XmlEditor.Clear(); XmlEditor.Text = IndentXml(); UnselectSelectedItem(); XmlTree.Items.Refresh(); XmlTree.UpdateLayout(); } private void UnselectSelectedItem() { if (XmlTree.SelectedItem != null) { var container = FindTreeViewSelectedItemContainer(XmlTree, XmlTree.SelectedItem); if (container != null) { container.IsSelected = false; } } } private static TreeViewItem FindTreeViewSelectedItemContainer(ItemsControl root, object selection) { var item = root.ItemContainerGenerator.ContainerFromItem(selection) as TreeViewItem; if (item == null) { foreach (var subItem in root.Items) { item = FindTreeViewSelectedItemContainer((TreeViewItem)root.ItemContainerGenerator.ContainerFromItem(subItem), selection); if (item != null) { break; } } } return item; }