How to Drag and Drop Rows Between WPF DataGrid and WPF TreeGrid?

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

To perform the dragging operation between DataGrid and TreeGrid by using the GridRowDragDropController.Drop and TreeGridRowDragDropController.Drop events.

this.sfDataGrid.RowDragDropController.Drop += sfDataGrid_Drop;
this.sfTreeGrid.RowDragDropController.Drop += sfTreeGrid_Drop;

/// <summary>
/// Customized TreeGrid Drop event.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void sfTreeGrid_Drop(object sender, TreeGridRowDropEventArgs e)
{
    if (e.IsFromOutSideSource)
    {
        var draggingRecord = e.Data.GetData("Records") as ObservableCollection<object>;
        var record = draggingRecord[0] as EmployeeInfo;
        var dropPosition = e.DropPosition.ToString();
        var newItem = new EmployeeInfo();
        var rowIndex =AssociatedObject.sfTreeGrid.ResolveToRowIndex(e.TargetNode.Item);
        if (dropPosition != "None" && rowIndex != -1)
        {
            if (AssociatedObject.sfTreeGrid.View is TreeGridSelfRelationalView)
            {
                var treeNode = e.TargetNode;
                if (treeNode == null)
                    return;
                var data = treeNode.Item;
                AssociatedObject.sfTreeGrid.SelectionController.SuspendUpdates();
                var dropIndex = -1;
                TreeNode parentNode = null;
                if (dropPosition == "DropBelow" || dropPosition == "DropAbove")
                {
                    parentNode = treeNode.ParentNode;
                    if (parentNode == null)
                    {
                        var treeNodeItem = treeNode.Item as EmployeeInfo;
                        newItem = new EmployeeInfo() { FirstName = record.FirstName, LastName = record.LastName, ID = record.ID, Salary = record.Salary, Title = record.Title, ReportsTo = treeNodeItem.ReportsTo };
                    }
                    else
                    {
                        var parentNodeItems = parentNode.Item as EmployeeInfo;
                        newItem = new EmployeeInfo() { FirstName = record.FirstName, LastName = record.LastName, ID = record.ID, Salary = record.Salary, Title = record.Title, ReportsTo = parentNodeItems.ID };
                    }
                }
                else if (dropPosition == "DropAsChild")
                {
                    if (!treeNode.IsExpanded)
                        AssociatedObject.sfTreeGrid.ExpandNode(treeNode);
                    parentNode = treeNode;
                    var parentNodeItems = parentNode.Item as EmployeeInfo;
                    newItem = new EmployeeInfo() { FirstName = record.FirstName, LastName = record.LastName, ID = record.ID, Salary = record.Salary, Title = record.Title, ReportsTo = parentNodeItems.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);
                    }
                    dropIndex = sourceCollection.IndexOf(data);
                    if (dropPosition == "DropBelow")
                    {
                        dropIndex += 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;
                        }
                    }
                    dropIndex = sourceCollection.Count;
                }
                sourceCollection.Insert(dropIndex, newItem);
                AssociatedObject.sfTreeGrid.SelectionController.ResumeUpdates();
                (AssociatedObject.sfTreeGrid.SelectionController as TreeGridRowSelectionController).RefreshSelection();
                e.Handled = true;
            }
        }
        AssociatedObject.sfDataGrid.View.Remove(record);
    }
}

/// <summary>
/// Gets the source collection of TreeGrid
/// </summary>
/// <param name="collection"></param>
/// <returns></returns>
private IList GetSourceListCollection(IEnumerable collection)
{
    IList list = null;
    if (collection == null)
        collection = AssociatedObject.sfTreeGrid.View.SourceCollection;
    if ((collection as IList) != null)
    {
        list = collection as IList;
    }
    return list;
}

/// <summary>
/// Customize the Drop event.restrict the certain record and Drop position from drop.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void sfDataGrid_Drop(object sender, GridRowDropEventArgs e)
{
    if (e.IsFromOutSideSource)
    {
        var draggingRecord = e.Data.GetData("Nodes") as ObservableCollection<TreeNode>;
        var record = draggingRecord[0].Item as EmployeeInfo;
        int dropIndex = (int)e.TargetRecord;
        var dropPosition = e.DropPosition.ToString();
        if (record.Title == "Manager")
        {
            e.Handled = true;
            return;
        }
        IList collection = null;
        collection = AssociatedObject.sfDataGrid.View.SourceCollection as IList;
        if (dropPosition == "DropAbove")
        {
            dropIndex--;
            collection.Insert(dropIndex, record);
        }
        else
        {
            dropIndex++;
            collection.Insert(dropIndex, record);   
        }
        AssociatedObject.sfTreeGrid.View.Remove(record);
        e.Handled = true;
    }
}