I am running into an issue involving containers and dragging a selection.

Open the attached zip file and import the xml into the MindFusion Demo program. There are two containers on the screen, with a shapenode inside of the right one.

Hold control, and then select both the right container AND the node inside of it.

Select and drag the two selected items into the container on the right.

Collapse the inner container and the shapenode that was inside of it when you dragged it is no longer inside of it. In our product shapenodes are getting dropped into the wrong container in various scenarios like this, involving more than one item selected and dragged into a container.

This behavior did not used to happen in an older build of our product using an older version of MindFusion.

We upgraded to 6.0 from 5.6.2.

The following changes in ContainerNode.cs will fix that:

Replace the two GetFoldedContainer methods with

/// <summary>
/// Retrieves the topmost folded container node (if any)
/// the specified node belongs to.
/// </summary>
internal static ContainerNode GetFoldedContainer(DiagramNode node)
{
	return FindTopmostContainer(node, null,
		delegate(ContainerNode c) { return c.Folded; });
}

/// <summary>
/// Retrieves the topmost selected container node (if any)
/// the specified node belongs to.
/// </summary>
internal static ContainerNode GetSelectedContainer(DiagramNode node)
{
	return FindTopmostContainer(node, null,
		delegate(ContainerNode c) { return c.Selected; });
}

static private ContainerNode FindTopmostContainer(
	DiagramNode node, ContainerNode topmost, Predicate<ContainerNode> condition)
{
	ContainerNode container = GetContainer(node);
	if (container != null)
	{
		if (condition(container))
			return FindTopmostContainer(container, container, condition);

		return FindTopmostContainer(container, topmost, condition);
	}

	return topmost;
} 

and in OnDropOver override replace nodes = selection.Nodes.Clone() assignment with

nodes = new DiagramNodeCollection();
foreach (DiagramNode node in selection.Nodes)
	if (GetSelectedContainer(node) == null)
		nodes.Add(node); 

In effect, that should change the parent only of the outermost selected container.

I hope that helps,
Stoyan