Hi,

I tried to combine the 2 telerik examples related to RadTreeviews - the RadTreeView as File Explorer and that from SDK repo related to drag and drop between 2 Radtreeview.

I finally succeeded to make an working short program, but I don't know why by dragging a file from one tree to another, the UI of the second tree shows the dropped file twice - even the Tree ItemsSource is correct (only one file dragged and dropped)

after Puplating the trees,I used DragDropMAnager and the following classes (as they are defined in telerik example, adapted to files/folder structure)

DragDropManager.AddDragOverHandler(this.tree1, OnTree1DragOver, true);
DragDropManager.AddDragOverHandler(this.tree2, OnTree2DragOver, true);
DragDropManager.AddDropHandler(this.tree2, OnTree2Drop, true);

My OnTree2DragOver function:

var options = DragDropPayloadManager.GetDataFromObject(e.Data, TreeViewDragDropOptions.Key) as TreeViewDragDropOptions;
if (options == null)
    return;

// The condition after the first OR operator is needed to deny the drop of items in Application File. (sub-items)
RadTreeViewItem dropTargetItem = options.DropTargetItem;

var draggedItem = options.DraggedItems.First();
if (dropTargetItem == null ||
(dropTargetItem != null &&
     options.DropTargetItem.DataContext is File &&
     options.DropPosition == DropPosition.Inside) ||
    draggedItem is Folder)
{
    options.DropAction = DropAction.None;
}

options.UpdateDragVisual();

my OnTree2Drop function is:

 var options = DragDropPayloadManager.GetDataFromObject(e.Data, TreeViewDragDropOptions.Key) as TreeViewDragDropOptions;
 if (options == null)
     return;
 File draggedItem = options.DraggedItems.FirstOrDefault() as File;
 if (draggedItem == null)
     return;
 RadTreeViewItem dropTargetItem = options.DropTargetItem;
 if (dropTargetItem == null)
     return;
 var dropItemModel = dropTargetItem.DataContext;
 if (dropItemModel == null)
     return;
 var dropTree = sender as RadTreeView;
 if (dropTree != null)
 {
     // Disable drop in tree2 File.
     if (dropItemModel is File && options.DropAction == DropAction.None)
     {
         e.Handled = true;
         return;
     }
     //Drop in tree2
     if (dropItemModel is Folder || dropItemModel is File)
     {
         options.DropAction = DropAction.Copy;
         //options.UpdateDragVisual();
         Folder destinationFolder = null;
         if (dropItemModel is Folder)
         {
             // Dropping inside Application.
             destinationFolder = dropItemModel as Folder;
         }
         else
         {
             // Dropping Before or After an Application Resource.
             destinationFolder = options.DropTargetItem.ParentItem.DataContext as Folder;
         }
         if (destinationFolder == null)
         {
             return;
         }
         File file = new File()
         {
             Name = draggedItem.Name
         };
         destinationFolder.Items.Add(file);
    
         //options.UpdateDragVisual();
     
         System.IO.File.Copy(@draggedItem.FullPath, System.IO.Path.Combine(@destinationFolder.FullPath, System.IO.Path.GetFileName(@draggedItem.FullPath)));
         options.UpdateDragVisual();

My OnTree1DragOver:

var options = DragDropPayloadManager.GetDataFromObject(e.Data, TreeViewDragDropOptions.Key) as TreeViewDragDropOptions;
if (options != null)
{
    options.DropAction = DropAction.None;
    options.UpdateDragVisual();
    var draggedFile = options.DraggedItems.First() as File;
    e.Handled = true;
}

In the attached picture you'll see Adeliatte Italic.ttf twice, even I dragged and drpped it only once.

Could you please take a short look and tell me what I'm doing wrong?

Or, if it is not too much time consuming for you to come back with an example of 2 treeviews acting as explorer and with d&d functionality?

Thank you in advance for your support.

Danny

<telerik:RadBusyIndicator x:Name="radBusyIndicator"
                          Foreground="#ffffff"
                          IsBusy="{Binding IsBusy}">

I use the above when to show the busy indicator while saving.

After it has saved (IsBusy is false) I call Element.Focus(); but it does not focus on the element.
No element shows as being focused.

If I remove the line that sets IsBusy to true the focus works as expected.

Is there a workaround for this problem? 

This should be trivial, but.... I see an old question about this at HorizontalContentAlignment doesn't work in UI for WPF | Telerik Forums.  When I download the sample, it works as advertised, even if I upgrade to the latest.  However, in my project I can't seem to get the text to right-justify.  This is a direct copy of my XAML:

<telerik:RadNumericUpDown Grid.Row="9" Grid.Column="1" Width="100" NumberDecimalDigits="0" Value="{Binding MyIntField}" HorizontalContentAlignment="Right" />

And yet...

If I inspect the field in the live tree, "HorizontalContentAlignment" shows "Right".

What have I got wrong?

When reading https://docs.telerik.com/devtools/wpf/controls/radgridview/hierarchical-gridview/self-referencing-grid I was expecting that `Self-Referencing` RadGridView means it uses own columns and rest visual stuff to display all nested child RadGridViews. Since it references the same type in the underlying data on every hierarchy level (that is self-referencing), it's obviously should display all levels in the same way (as it displays itself on top-level). 

Turned out it was not the case. Each child level requires own visual template, own columns with own styling. We have about 20 columns with heavy styling each (more than 500 lines in .xaml) for top-level `RadGridView`. Copy-pasting all that into `RadGridView.HierarchyChildTemplate` is not an option.

In your demo application, I saw that you add columns manually for a child `RadGridView` from `RadGridView1_DataLoading` handler in code-behind. I was hoping it was a mistake.

I was looking at the https://www.telerik.com/forums/preview-(and-stop)-selectionchanged post from 5 years ago. In the first answer, there was an attached solution to the problem. If using the ItemsSource binding, you could prevent the change by not firing the OnPropertyChanged event.

I loaded this project using the 2025Q1 dlls and while the SelectedItem may not technically update, the UI reflects that the item is selected. Is there an updated solution to this?

Hi,

The radwindow does not show up unless I put Style="{DynamicResource RadWindowStyle}".

May I ask where do I put theme for my radwindow?

And how do I change the radwindowstyle? It shows up the minimize, close button on the left side but I would want it to put on the right side of the window.

Hello,

In our app we are using filtering through a RadGridView bound to a QueryableCollectionView that wraps an ObservableCollection. Now I'm trying to use that filtered QueryableCollectionView as the ItemSource for a VisualizationLayer in a RadMap so that the filter on the grid also applies to items shown on the map, but the bind fails with the following error: "System.ArgumentException: 'Telerik.Windows.Data.QueryableCollectionView' is not a valid value for property 'Source'."

I've attached a quick project replicating the issue with the relevant code in MainWindow.xaml:

            <!-- Doesn't work -->
            <telerik:VisualizationLayer ItemsSource="{Binding ItemViewModelsView }" ItemSelectionMode="None">
                <telerik:VisualizationLayer.ItemTemplate>
                    <DataTemplate DataType="{x:Type local:ItemViewModel}">
                        <Ellipse Fill="Blue" Width="12" Height="12" telerik:MapLayer.Location="{Binding Location}"/>
                    </DataTemplate>
                </telerik:VisualizationLayer.ItemTemplate>
            </telerik:VisualizationLayer>
            
            <!-- Also doesn't work pulling directly from the GridView -->
            <telerik:VisualizationLayer ItemsSource="{Binding Items, ElementName=GridView }" ItemSelectionMode="None">
                <telerik:VisualizationLayer.ItemTemplate>
                    <DataTemplate DataType="{x:Type local:ItemViewModel}">
                        <Ellipse Fill="Blue" Width="12" Height="12" telerik:MapLayer.Location="{Binding Location}"/>
                    </DataTemplate>
                </telerik:VisualizationLayer.ItemTemplate>
            </telerik:VisualizationLayer>
            
            <!-- Works but isn't filtered -->
            <telerik:VisualizationLayer ItemsSource="{Binding ItemViewModels }" ItemSelectionMode="None">
                <telerik:VisualizationLayer.ItemTemplate>
                    <DataTemplate DataType="{x:Type local:ItemViewModel}">
                        <Ellipse Fill="Blue" Width="12" Height="12" telerik:MapLayer.Location="{Binding Location}"/>
                    </DataTemplate>
                </telerik:VisualizationLayer.ItemTemplate>
            </telerik:VisualizationLayer>

and the ViewModel:

public partial class MainWindowViewModel : ObservableObject
{
    [ObservableProperty] private ObservableCollection<ItemViewModel> _itemViewModels;
    public QueryableCollectionView ItemViewModelsView { get; private set; }
//...
}

It appears to me that the issue is because QueryableCollectionView is both an IEnumerable and a ICollectionView so when it tries to assign it to the MapItemsSource the CollectionViewSource.IsSourceValid() that's called during that assignment is returning false because it is an ICollectionView.

Is there a known workaround for this or suggested alternative to get the expected functionality?

Thanks!

RadGridView, for WPF .NET Framework 4.8, automatically hides rows that do not match the filter/search criteria after a row has been edited. How does one prevent the auto-filtering/searching?

A very important workflow for our customers is to search / filter for outliers and then edit the found rows. After they finish editing, they don't want the row to automatically disappear because of the search / filter doesn't match the row after the edits.

The customer only wants to search / filter if they actually initiated the action. They do not want auto searching and filtering.