How to disable map from being scrolled in windows phone8.1?

Hi

In a button click event ,want to disable the map being scrolled/dragged/Zoomed.

I tried MyMap.IsHitTestVisible = false; and MyMap.IsEnabled = false;

But both didn't work.How to disable the map being scrolled/dragged/Zoomed.

My Code:

HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >

Code Behind:

private void Stop_Click(object sender, RoutedEventArgs e)
{

grdMyMap.IsHitTestVisible = false;
}