Code

private void diagViewL_MouseMove(object sender, MouseEventArgs e)
{
	if (e.Button != MouseButtons.Left)
		return;

	if ((Control.ModifierKeys & Keys.Shift) == 0)
		return;

	DiagramNode node = diagL.GetNodeAt(diagViewL.ClientToDoc(e.Location));
	if (diagL.Interaction != null)
		diagL.Interaction.Cancel(diagL);

	if (diagL.Selection.Nodes.Count > 1)
	{
		Diagram diagTemp = new Diagram();
		SelectionCopy copy = diagL.CopySelection(diagL, false, false);
		diagTemp.PasteSelection(diagTemp, copy, null, 0, 0);

		DoDragDrop(diagTemp.SaveToString(), DragDropEffects.Copy);
	}
	else if (node != null && node is ShapeNode)
	{
		DoDragDrop(node as ShapeNode, DragDropEffects.Copy);
	}
}

private void diagViewR_DragOver(object sender, DragEventArgs e)
{
	if (e.Data.GetDataPresent("System.String"))
	{
		e.Effect = DragDropEffects.Copy;
	}
	else if (e.Data.GetDataPresent("MindFusion.Diagramming.ShapeNode"))
	{
		e.Effect = DragDropEffects.Copy;
	}
	else
	{
		e.Effect = DragDropEffects.None;
	}
}

private void diagViewR_DragDrop(object sender, DragEventArgs e)
{
	if (e.Data.GetDataPresent("System.String"))
	{
		string s = e.Data.GetData("System.String") as string;
		Diagram diagTemp = new Diagram();
		diagTemp.LoadFromString(s);
		SelectionCopy copy = diagTemp.CopySelection(diagTemp, false, false);

		PointF pt = diagViewR.ClientToDoc(Control.MousePosition);
		diagR.PasteSelection(diagR, copy, null, 0, 0);
	}
	else if (e.Data.GetDataPresent("MindFusion.Diagramming.ShapeNode"))
	{
		if (e.Effect == DragDropEffects.Copy)
		{
			ShapeNode node = e.Data.GetData("MindFusion.Diagramming.ShapeNode") as ShapeNode;

			Point p = diagViewR.PointToClient(new Point(e.X, e.Y));
			PointF pt = diagViewR.ClientToDoc(new Point(p.X, p.Y));

			diagR.Nodes.Add(new ShapeNode(node));
			MessageBox.Show(diagL.Nodes.Count.ToString());
		}
	}
}
 

Code

private void diagL_NodeStartModifying(object sender, NodeValidationEventArgs e)
{
	if (e.AdjustmentHandle == AdjustmentHandles.Move)
	{
		e.CancelDrag();
		DoDragDropSelection();
	}
}

private void diagL_SelectionMoving(object sender, ValidationEventArgs e)
{
	DoDragDropSelection();
}

private void DoDragDropSelection()
{
	Diagram diagTemp = new Diagram();
	SelectionCopy copy = diagL.CopySelection(diagL, false, false);
	diagTemp.PasteSelection(diagTemp, copy, null, 0, 0);

	DoDragDrop(diagTemp.SaveToString(), DragDropEffects.Copy);
}