How to Drag and Drop Between Two WinUI TreeView?

This example describes how to drag and drop between two WinUI TreeView (SfTreeView).

You can customize the dragging operation between two treeview by using the SfTreeView.ItemDragStarting, SfTreeView.ItemDropping and SfTreeView.ItemDropped events.

AssociatedObject.sfTreeView1.ItemDragStarting += SfTreeView1_ItemDragStarting;    
AssociatedObject.sfTreeView1.ItemDropping += SfTreeView1_ItemDropping;
AssociatedObject.sfTreeView2.ItemDropping += SfTreeView2_ItemDropping;
AssociatedObject.sfTreeView2.ItemDropped += SfTreeView1_ItemDropped;
    
/// <summary>
/// Customizing the ItemStarting event
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void SfTreeView1_ItemDragStarting(object sender, Syncfusion.UI.Xaml.TreeView.TreeViewItemDragStartingEventArgs e)
{
    //Restrict the dragging for certain node
    var record = e.DraggingNodes[0].Content as Model;
    if (record.Header == "Feature Schedule")
        e.Cancel = true;
}

/// <summary>
/// Customizing the ItemDropping event
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void SfTreeView1_ItemDropping(object sender, Syncfusion.UI.Xaml.TreeView.TreeViewItemDroppingEventArgs e)
{
    //Restrict the dropping in first treeview
    e.Handled = true;
}

/// <summary>
/// Customizing the ItemDropping event
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void SfTreeView2_ItemDropping(object sender, Syncfusion.UI.Xaml.TreeView.TreeViewItemDroppingEventArgs e)
{
    //Restrict the dropping for drop position as above
    if (e.DropPosition == Syncfusion.UI.Xaml.TreeView.DropPosition.DropAbove)
        e.Handled = true;

    //Restrict the dropping on certain nodes
    var record = e.TargetNode.Content as Model;
    if (record.Header == "My Folders")
        e.Handled = true;
}

/// <summary>
/// Customize the ItemDropped event
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void SfTreeView1_ItemDropped(object sender, Syncfusion.UI.Xaml.TreeView.TreeViewItemDroppedEventArgs e)
{
    var parentNode = e.TargetNode.ParentNode;
    var collection = parentNode.ChildNodes;
    var record = e.DraggingNodes[0].Content as Model;
    int count = 0;
    foreach (var child in parentNode.ChildNodes)
    {
        var childNode = child.Content as Model;
        if (childNode.Header == record.Header)
        {
            count++;
            if (count > 1)
            {
            // Remove dropped node if the parent has the same node in it
                collection.Remove(child);
                return;
            }
        }
    }
}