Comment sélectionner une TreeViewItem de databound?

Question

J'ai une base de données XML vers un TreeView avec un XmlDataProvider. Si j'ajoute un sous-noeud au XML, TreeView le montre, mais comment puis-je sélectionner cet élément?

XAML:

<Window.Resources> 
    <HierarchicalDataTemplate DataType="category" ItemsSource="{Binding XPath=child::node()}"> 
     <TextBlock Text="{Binding XPath=@name}" FontWeight="Bold" /> 
    </HierarchicalDataTemplate> 

    <HierarchicalDataTemplate DataType="card"> 
     <TextBlock Text="{Binding XPath=./title}" FontStyle="Italic" /> 
    </HierarchicalDataTemplate> 

    <XmlDataProvider x:Key="dataxml" XPath="root/cards"/> 

</Window.Resources> 

<TreeView Name="treeView" 
      ItemsSource="{Binding Source={StaticResource dataxml}, 
          XPath=./*, 
          UpdateSourceTrigger=PropertyChanged}" 
/> 

CS:

public partial class MainWindow : Window 
{ 
    XmlDataProvider xmlDataProvider = new XmlDataProvider(); 

    public MainWindow() 
    { 
     InitializeComponent();   
     xmlDataProvider = this.FindResource("dataxml") as XmlDataProvider; 
     xmlDataProvider.Source = new Uri(System.IO.Path.GetFullPath(fullPathToXml), UriKind.Absolute); 
     xmlDataProvider.Refresh(); 
    } 

    public void AddChild() 
    { 
     XmlNode newNode = xmlDataProvider.Document.CreateElement("card"); 
     XmlNode selectedItem = (XmlNode)treeView.SelectedItem; 

     if (selectedItem != null) 
     { 
      //add the newNode as child to the selected 
      selectedItem.AppendChild(newNode); 
      //select the childnode (newNode) ?????  <===== 
     } 
     else 
     { 
      //add the newNode as child to the rootnode and select it: 
      xmlDataProvider.Document.DocumentElement["cards"].AppendChild(newNode); 
      (treeView.ItemContainerGenerator.ContainerFromItem(newNode) as TreeViewItem).IsSelected = true; 
     } 

     xmlDataProvider.Document.Save(fullPathToXml); 
     xmlDataProvider.Refresh(); 
    } 
} 

XML:

<root> 
    <settings> 
    .... 
    .. 
    </settings> 
    <cards> 
    <category name="C1"> 
     <card name="card1"> 
      <question>bla</question> 
      <answer>blub</answer> 
     </card> 
     <category name="C2"> 
      <card name="card4"> 
       <question>bla</question> 
       <answer>blub</answer> 
      </card> 
     </category> 
    </category> 
     <card name="card2"> 
      <question>bla</question> 
      <answer>blub</answer> 
     </card> 
     <card name="card3"> 
      <question>bla</question> 
      <answer>blub</answer> 
     </card> 
    </cards> 
</root> 

Answer 1

Il est tard, donc mes fonctions ne sont pas les plus fluides, mais ça marche! J'ai des commentaires pour tous ceux qui ont une fois le même problème ;-)

usings:

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Windows.Controls; 
using System.Xml; 
using System.Runtime.InteropServices; 

Fonction:

/// <summary> 
/// Select a XmlNode in a TreeView that is databound to a xmlDataProvider. 
/// </summary> 
/// <param name="treeView">A referenz to the TreeView.</param> 
/// <param name="node">The node to select.</param> 
public static void SelectTreeViewNode(ref TreeView treeView, XmlNode node) 
{ 
    if (treeView.HasItems) 
    { 
     //cast to xml-nodes 
     var xmlNodeList = treeView.Items.Cast<XmlNode>(); ; 

     //node at root level? -> select it 
     if (xmlNodeList.Contains(node)) 
     { 
      (treeView.ItemContainerGenerator.ContainerFromItem(node) as TreeViewItem).IsSelected = true; 
     } 
     else 
     { 
      //get rootnode 
      XmlNode rootNode = GetRootNode(node, xmlNodeList); 

      //get a list of parent nodes 
      List<XmlNode> parentNodes = new List<XmlNode>(); 
      GetAllParentNodes(rootNode, node, ref parentNodes); 
      parentNodes.Reverse(); 

      //finaly, select the node 
      SelectNode(parentNodes, node, ref treeView, null); 
     } 

    } 
} 

/// <summary> 
/// Goes recursiv down the parent nodes until he finds a node that is in the xmlNodeList. 
/// Returns null if he can´t find anything. 
/// </summary> 
/// <param name="node">The start node.</param> 
/// <param name="xmlNodeList">A list with possible rootnodes.</param> 
/// <returns>The rootnode</returns> 
private static XmlNode GetRootNode(XmlNode node, IEnumerable<XmlNode> xmlNodeList) 
{ 
    if (!xmlNodeList.Contains(node) && node.ParentNode != null) 
    { 
     return GetRootNode(node.ParentNode, xmlNodeList); 
    } 
    else if (xmlNodeList.Contains(node)) return node; 
    else return null; 
} 

/// <summary> 
/// Returns all parent nodes from the actual node within the rootNode. Works recursiv. 
/// </summary> 
/// <param name="rootNode">The rootnode.</param> 
/// <param name="actualNode">The startnode</param> 
/// <param name="parentNodes">The rererenz to the outputlist</param> 
private static void GetAllParentNodes(XmlNode rootNode, XmlNode actualNode, ref List<XmlNode> parentNodes) 
{ 
    if (actualNode.ParentNode != null && !actualNode.Equals(rootNode)) 
    { 
     parentNodes.Add(actualNode.ParentNode); 
     GetAllParentNodes(rootNode, actualNode.ParentNode, ref parentNodes); 
    } 
} 

/// <summary> 
/// Select a XmlNode from a TreeView that is databound to a xmlDataProvider. 
/// </summary> 
/// <param name="parentNodes">All the parent nodes, first in the list is the rootnode.</param> 
/// <param name="node">The node to select.</param> 
/// <param name="treeView">A referenz to the TreeView.</param> 
/// <param name="item">Variable for the recursion.</param> 
private static void SelectNode(List<XmlNode> parentNodes, XmlNode node, ref TreeView treeView, [Optional, DefaultParameterValue(null)] TreeViewItem item) 
{ 
    if (parentNodes.Count > 0) 
    { 
     TreeViewItem tvItem; 
     if (item != null) 
      tvItem = item.ItemContainerGenerator.ContainerFromItem(parentNodes.First()) as TreeViewItem; 
     else 
      tvItem = treeView.ItemContainerGenerator.ContainerFromItem(parentNodes.First()) as TreeViewItem; 
     parentNodes.RemoveAt(0); 
     SelectNode(parentNodes, node, ref treeView, tvItem); 
    } 
    else if (item != null) 
    { 
     (item.ItemContainerGenerator.ContainerFromItem(node) as TreeViewItem).IsSelected = true; 
    } 
} 

Answer 2

Cette blog post décrit comment sélectionner un élément. Fondamentalement, vous ne pouvez pas simplement utiliser TreeView.ItemContainerGenerator, car cela vous donne juste accès à la racine TreeViewItems. Les TreeViewItems imbriqués sont accessibles à l'aide de TreeViewItem.ItemContainerGenerator du TreeViewItem parent.

Answer 3

J'ai une première approche:

((treeView.ItemContainerGenerator.ContainerFromIndex(1) as TreeViewItem).ItemContainerGenerator.ContainerFromItem(newNode) as TreeViewItem).IsSelected = true; 

Sélectionne le newNode si je l'ajouter à la catégorie sur la position 1, sinon je deviens une exception ;-)

maintenant je travaille sur une dynamique une fois avec plus d'un niveau :-)