Sampling the PositionChanged Event with Rx

If the GeoCoordinateWatcher class is assigned too low a MovementThreshold value, the event handler for the GeoCoordinateWatcher.PositionChanged event may be raised more frequently than needed, which can potentially degrade the performance of your app. The Reactive Extensions (Rx) can eliminate this issue by modulating, or sampling, the event, restricting calls to the PositionChanged event handler to a certain number each second.

Rx is a managed library that has been included as part of the Windows Phone Framework Class Library (FCL). At its essence, Rx allows events to be treated as a data stream. Rx allows you to subscribe to this data stream, and to manipulate and filter the data stream before it is handled by your app.