The latest addition to the “Build Charming Apps for Windows Phone” libraries addresses a couple of properties required to support different screen sizes. I decided I wanted a simple way to retrieve the DPI and Scale factor (real not emulated) while working smoothly on devices prior to GDR3 where 1080p support was added. The result is a single class – DisplayInformation which (true to theme) follows the Windows 8.1 object model.
Some of the properties found in the desktop implementation make no sense – there isn’t support for Stereoscopic output for example. So just three properties are exposed – RawDpiX, RawDpiY and ResolutionScale. One additional member is added to the ResolutionScale enumeration as desktop Windows has no concept of 2.25 scale factor but this is used for 1080p Windows Phone devices. It’s not always possible to provide a perfect API match to the desktop and this seemed like a good workaround. These will call into the extended properties in GDR3 where possible but will equally work correctly on older devices.
The library is up on NuGet here.