DataGrid and GridSplitter in Silverlight 4

I have a grid with tow rows splitting with the gridspli开发者_如何学编程tter. In first row I'm showing the datagrid with datapager and its Vertical Alignment is set to stretch. In the second row I'm displaying the DataForm as Child in the Expander Control.

What I want is to occupy all space(vertically) by DataGrid when there is No Expander (DataForm Visibility) but Soon the User press the Expander to view the DataForm, it open's upward and the DataGrid to be shrinked so that the DataForm can be displayed.

At present when I click on the Expander, it does expand and show the dataForm but the datagrid size does not changed. Even I cannot make it smaller with the GridSplitter. It only goes upto the pagesize.

Any ideas what's wrong? OR is it because I cannot reduce as the datapager wants to display the specific number of rowns (15).

This looks like it overlaps your other question...

The same answer will likely apply to this one. Basically you have to constrain the overall size of your container/control, using An Auto-Sized row on the Expander and a Star-size row for the Grid.

as per the other question, I do not see why you would have a grid splitter in that configuration in the first place.