Read original post at Shawn Wildermuth's Blog
I am working with a client on an enterprise Win8 app that is for order taking. They have a specific page that they require to be only in Portrait mode while the rest of the app can support any orientation. Since I've done so much Windows Phone 7/8 work I thought this would be simple. Just specify the value on the Page. But this didn't work…
Digging through the docs I found a probable solution: DisplayProperties.AutoRotationPreferences (in the Windows.Graphics.Display namespace). The docs specify that this property can be set with the DisplayOrientations enumeration to specify which of the four orientations to support.