17
votes

I have a TreeView that is bound to a dataset which is having parent child relation. How i will get seleted TreeViewItem from the TreeView? Please help me. My code is below.

xaml:-

<TreeView Name="tvPersonal"  Background="Transparent"  ItemsSource="{Binding RootNodes}" SelectedItemChanged="tvPersonal_SelectedItemChanged">    
 <TreeView.ItemTemplate>
   <HierarchicalDataTemplate ItemsSource="{Binding rsParentChild}">
     <TextBlock Text="{Binding Name}" />
   </HierarchicalDataTemplate>
 </TreeView.ItemTemplate>

 public MainWindow()   

        {    
            InitializeComponent();    
            DataSet ds = new BL.BLMenu().GetAllMenues(new BOModule { Name = Modules.Personnel });
            ds.Tables[0].TableName = "Menu";
            DataRelation relation = new DataRelation("rsParentChild",
                    ds.Tables["Menu"].Columns["MenuId"],
                    ds.Tables["Menu"].Columns["ParentId"]);
            relation.Nested = true;    
            ds.Relations.Add(relation);
            BOMenu mnu = new BOMenu();    
            BOMenu.RootNodes = ds.Tables["Menu"].DefaultView;
            BOMenu.RootNodes.RowFilter = "ParentId IS NULL";    

            this.DataContext = this;
            stbiDate.Content = DateTime.Now;

        }
        public DataView RootNodes    
        {
            get { return BOMenu.RootNodes; }
        }

BOMenu Class :-

 public class BOMenu
    {
        public string MenuId
        {
            get;
            set;
        }

        public string Name
        {
            get;
            set;
        }

        public string ParentId
        {
            get;
            set;
        }

        public int Priority
        {
            get;
            set;
        }

        public static DataView RootNodes
        {
            get;
            set;
        }

    }
4

4 Answers

17
votes

While biju's answer works for flat hierarchies, I had to look for a solution for HierarchicalDataTemplates. This is the extension method that worked for me:

public static TreeViewItem ContainerFromItemRecursive(this ItemContainerGenerator root, object item)
{
    var treeViewItem = root.ContainerFromItem(item) as TreeViewItem;
    if (treeViewItem != null)
        return treeViewItem;
    foreach (var subItem in root.Items)
    {
        treeViewItem = root.ContainerFromItem(subItem) as TreeViewItem;
        var search = treeViewItem?.ItemContainerGenerator.ContainerFromItemRecursive(item);
        if (search != null)
            return search;
    }
    return null;
}

You can use it with

TreeViewItem tvi = treeView
                       .ItemContainerGenerator
                       .ContainerFromItemRecursive(treeView.SelectedItem);
13
votes

Try

TreeViewItem tvi = myTree.ItemContainerGenerator.ContainerFromItem(SelectedItem) as TreeViewItem;

or go through the below links.Hope this helps

Data binding to SelectedItem in a WPF Treeview

Get SelectedItem from TreeView?

http://social.msdn.microsoft.com/forums/en-US/wpf/thread/36aca7f7-0b47-488b-8e16-840b86addfa3/

8
votes

This works for trees whose data source is bound via a HierarchicalDataTemplate

Handle TreeViewItem.Selected

<TreeView Name="mTreeView" TreeViewItem.Selected="TreeViewItem_OnItemSelected" />

And set the TreeViewItem as the Tag.

private void TreeViewItem_OnItemSelected(object sender, RoutedEventArgs e)
{
    mTreeView.Tag = e.OriginalSource;
}

Which you can retrieve later

TreeViewItem tvi = mTreeView.Tag as TreeViewItem;
1
votes

The best solution I've found involves a simple helper method and can be used in virtually any of the TreeView's events (i.e., SelectedItemChanged, MouseLeftButtonUp, etc.).

TreeViewItem Item = TreeViewHelper.VisualUpwardSearch(e.OriginalSource as DependencyObject);

I am using multiple hierarchy data templates and this is the only method that worked for me. Now, I'm able to create a new control based on TreeView and can handle all events involving the selected item internally.

public static TreeViewItem VisualUpwardSearch(DependencyObject source)
{
    while (source != null && !(source is TreeViewItem)) source = System.Windows.Media.VisualTreeHelper.GetParent(source);
    return source as TreeViewItem;
}