Disable WPF TreeView (or TreeViewItem) selection?

问题:

Is there a nice way (except retemplating the whole TreeViewItem.Template) to disable selection in TreeView?

I am basically looking for the ItemsControl style of the TreeView (An ItemsControl is the best use to 'disable' selection on ListBox, read this post)

回答1:

Whenever an item is selected, you could "unselect" it. Ex. modify the code from http://www.codeproject.com/KB/WPF/TreeView_SelectionWPF.aspx or use a MVVM approach (see http://www.codeproject.com/KB/WPF/TreeViewWithViewModel.aspx) and always set IsSelected back to false.

回答2:

Try this:

<Trigger Property="HasItems" Value="true">
   <Setter Property="Focusable" Value="false" />
</Trigger>

回答3:

Based off of the links to the currently accepted answer, I implemented this in my project:

<ListView.ItemContainerStyle>
    <Style TargetType="{x:Type ListViewItem}">
        <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
    </Style>
</ListView.ItemContainerStyle>

Works for TreeViewItem as well. And in the view model:

protected bool _DisableSelection;
private bool _IsSelected;
public bool IsSelected
{
    get { return _IsSelected; }
    set
    {
        if (value == _IsSelected) return;
        _IsSelected = _DisableSelection ? false : value;
        NotifyPropertyChanged();
    }
}

Now you don't have to go hunting!

回答4:

This did the trick for me (based on this answer, but no tied to item - selection is disabled whatsoever):

<TreeView>
  <TreeView.ItemContainerStyle>
    <Style TargetType="TreeViewItem">
      <Setter Property="Focusable" Value="False" />
    </Style>
  </TreeView.ItemContainerStyle>
</TreeView>

回答5:

I decided to write a reusable behavior, HTH:

Namespace Components
  Public NotInheritable Class TreeViewBehavior

    Public Shared Function GetIsTransparent(
      ByVal element As TreeViewItem) As Boolean
      If element Is Nothing Then Throw New ArgumentNullException("element")
      Return element.GetValue(IsTransparentProperty)
    End Function
    Public Shared Sub SetIsTransparent(ByVal element As TreeViewItem,
                                       ByVal value As Boolean)
      If element Is Nothing Then Throw New ArgumentNullException("element")
      element.SetValue(IsTransparentProperty, value)
    End Sub
    Public Shared ReadOnly IsTransparentProperty As DependencyProperty =
      DependencyProperty.RegisterAttached("IsTransparent", GetType(Boolean),
        GetType(TreeViewBehavior),
        New FrameworkPropertyMetadata(False,
          AddressOf IsTransparent_PropertyChanged))
    Private Shared Sub IsTransparent_PropertyChanged(
      ByVal sender As Object, ByVal e As DependencyPropertyChangedEventArgs)
      Dim tvi = DirectCast(sender, TreeViewItem)
      Dim isTransparent = CBool(e.NewValue)

      If isTransparent Then
        AddHandler tvi.Selected, AddressOf tvi_Selected
      Else
        RemoveHandler tvi.Selected, AddressOf tvi_Selected
      End If
    End Sub
    Private Shared Sub tvi_Selected(ByVal sender As Object,
                                    ByVal e As RoutedEventArgs)
      Dim treeViewItem = DirectCast(sender, TreeViewItem)
      If Not treeViewItem.IsSelected Then Exit Sub

      treeViewItem.Dispatcher.Invoke(
        Sub(tvi As TreeViewItem) tvi.IsSelected = False,
        System.Windows.Threading.DispatcherPriority.Send,
        treeViewItem)
    End Sub

  End Class
End Namespace

Usage:

<Window xmlns:components="clr-namespace:WpfApplication.Components">
  <TreeView>
    <TreeView.ItemContainerStyle>
      <Style TargetType="TreeViewItem">
        <Setter 
          Property="components:TreeViewBehavior.IsTransparent" 
          Value="True" />
      </Style>
    </TreeView.ItemContainerStyle>
  </TreeView>
</Window> 

回答6:

I just unselected the TreeViewItems as they get selected. I Use the TreeView only once. However if i added several placed I would consider looking into adding this to a Attacked Behavior.

Xaml:

<TreeView SelectedItemChanged="TreeView_SelectionChanged">

Code behind:

private void TreeView_SelectionChanged(object sender, RoutedEventArgs e)
{
    var myTreeView = sender as TreeView;
    if (myTreeView == null) return;
    var selectedItem = (TreeViewItem)myTreeView.SelectedItem;
    if (selectedItem ==null) return;
    selectedItem.IsSelected = false;
}

回答7:

I did this a differently than the accepted answer:

Lets say that you have a property in your ViewModel (say 'ShouldPreventSelection') Now when ShouldPreventSelection is true you want selection to be disabled:

In your TreeView fire the PreviewSelected event like so:

<TreeView Name="TreeView1"
     ...
     PreviewSelected="TreeView1_PreviewSelected"
     ..
/>

Then in the codebehind you can the following:

private void TreeView1_PreviewSelected(object sender, RoutedEventArgs e)
{
    MyViewModel myViewModel = TreeView1.DataContext as MyViewModel;
    if (myViewModel == null)
    {
        return;
    }
    if (myViewModel .ShouldPreventSelection)
    {
        e.Handled = true;
    }

}