You have to edit the ScrollViewer
's ControlTemplate
which should look like the one in this page : http://msdn.microsoft.com/en-us/library/aa970847(v=vs.110).aspx
In the ScrollViewer Control Template Example, you can see that the ScrollContentPresenter
is inside a Border
which is inside the first row of a 2-rows Grid
.
Setting the RowSpan
to 2 for this Border
would achieve the effect you want.