How to Drag and Drop Rows between WPF TreeGrid and WPF TreeViewAdv?

This example illustrates how to drag and drop rows in between WPF TreeGrid (SfTreeGrid) and WPF TreeViewAdv.

You can drag and drop the items between TreeViewAdv and TreeGrid by wiring the Drop and DragStart events from the TreeGridRowDragDropController class.

private void RowDragDropController_DragStart(object sender, TreeGridRowDragStartEventArgs e)
{
    e.Handled = true;
    var dataObject = new DataObject();
    dataObject.SetData("SourceTreeGrid", this.AssociatedObject.sfTreeGrid);
    dataObject.SetData("Nodes", e.DraggingNodes);
            
    foreach (var node in e.DraggingNodes)
    {
        if (node.HasChildNodes)
        {
            records.Add(node.Item as EmployeeInfo);
            GetChildNodes(node);
        }
        else
        {
            records.Add(node.Item as EmployeeInfo);
        }
    }

    dataObject.SetData(records);

    if(records!=null)
    DragDrop.DoDragDrop(this.AssociatedObject.sfTreeGrid, dataObject, DragDropEffects.Copy | DragDropEffects.Move);
    records.Clear();
}

private void RowDragDropController_Drop(object sender, TreeGridRowDropEventArgs e)
{
    if (e.IsFromOutSideSource)
    {
        ObservableCollection<object> item = e.Data.GetData(typeof(ObservableCollection<object>)) as ObservableCollection<object>;
        var record = item[0] as EmployeeInfo;
        var dropPosition = e.DropPosition.ToString();
        var newItem = new EmployeeInfo();

        var rowIndex = AssociatedObject.sfTreeGrid.ResolveToRowIndex(e.TargetNode.Item);
        int nodeIndex = (int)rowIndex;
        if (dropPosition != "None" && rowIndex != -1)
        {
            if (AssociatedObject.sfTreeGrid.View is TreeGridSelfRelationalView)
            {
                var treeNode = AssociatedObject.sfTreeGrid.GetNodeAtRowIndex(rowIndex);

                if (treeNode == null)
                    return;

                var data = treeNode.Item;
                AssociatedObject.sfTreeGrid.SelectionController.SuspendUpdates();
                var itemIndex = -1;

                TreeNode parentNode = null;

                if (dropPosition == "DropBelow" || dropPosition == "DropAbove")
                {
                    parentNode = treeNode.ParentNode;

                    if (parentNode == null)
                        newItem = new EmployeeInfo() { FirstName = record.FirstName, LastName = record.LastName, ID = record.ID, Salary = record.Salary, Title = record.Title, ReportsTo = -1 };
                    else
                    {
                        var parent = parentNode.Item as EmployeeInfo;
                        newItem = new EmployeeInfo() { FirstName = record.FirstName, LastName = record.LastName, ID = record.ID, Salary = record.Salary, Title = record.Title, ReportsTo = parent.ID };
                    }
                }
                else if (dropPosition == "DropAsChild")
                {
                    if (!treeNode.IsExpanded)
                        AssociatedObject.sfTreeGrid.ExpandNode(treeNode);

                    parentNode = treeNode;
                    var parent = parentNode.Item as EmployeeInfo;
                    newItem = new EmployeeInfo() { FirstName = record.FirstName, LastName = record.LastName, ID = record.ID, Salary = record.Salary, Title = record.Title, ReportsTo = parent.ID };

                }
                IList sourceCollection = null;

                if (dropPosition == "DropBelow" || dropPosition == "DropAbove")
                {
                    if (treeNode.ParentNode != null)
                    {
                        var collection = AssociatedObject.sfTreeGrid.View.GetPropertyAccessProvider().GetValue(treeNode.ParentNode.Item, AssociatedObject.sfTreeGrid.ChildPropertyName) as IEnumerable;
                        sourceCollection = GetSourceListCollection(collection);
                    }
                    else
                    {
                        sourceCollection = GetSourceListCollection(AssociatedObject.sfTreeGrid.View.SourceCollection);
                    }
                    itemIndex = sourceCollection.IndexOf(data);

                    if (dropPosition == "DropBelow")
                    {
                        itemIndex += 1;
                    }
                }
                else if (dropPosition == "DropAsChild")
                {
                    var collection = AssociatedObject.sfTreeGrid.View.GetPropertyAccessProvider().GetValue(data, AssociatedObject.sfTreeGrid.ChildPropertyName) as IEnumerable;

                    sourceCollection = GetSourceListCollection(collection);

                    if (sourceCollection == null)
                    {
                        var list = data.GetType().GetProperty(AssociatedObject.sfTreeGrid.ChildPropertyName).PropertyType.CreateNew() as IList;

                        if (list != null)
                        {
                            AssociatedObject.sfTreeGrid.View.GetPropertyAccessProvider().SetValue(treeNode.Item, AssociatedObject.sfTreeGrid.ChildPropertyName, list);
                            sourceCollection = list;
                        }
                    }
                    itemIndex = sourceCollection.Count;
                }
                sourceCollection.Insert(itemIndex, newItem);
                AssociatedObject.sfTreeGrid.SelectionController.ResumeUpdates();
                (AssociatedObject.sfTreeGrid.SelectionController as TreeGridRowSelectionController).RefreshSelection();
                e.Handled = true;
            }
        }
        (AssociatedObject.treeview.ItemsSource as ObservableCollection<EmployeeInfo>).Remove(record as EmployeeInfo);
    }
}

In TreeViewAdv, you need to wire the Drop event,

private void Treeview_Drop(object sender, DragEventArgs e)
{
    ObservableCollection<TreeNode> treeNodes = new ObservableCollection<TreeNode>();

    if (e.Data.GetDataPresent("Nodes"))
        treeNodes = e.Data.GetData("Nodes") as ObservableCollection<TreeNode>;

    EmployeeInfo item = new EmployeeInfo();

    if (treeNodes.Count == 0 || treeNodes == null)
        return;

    foreach (var node in treeNodes)
    {
        (AssociatedObject.sfTreeGrid.ItemsSource as ObservableCollection<EmployeeInfo>).Remove(node.Item as EmployeeInfo);
    }
}