Snap GPS to Street

In this sample we are going to handle the common case of snapping a point to a set of features in a layer. The common case for this is snapping real-time GPS points to road layers. GPS has an error factor and it's nice to display vehicles on a map snapped to the roads they are on. It can also be used for a number of other different cases as well, such as finding not just the road position but the road name. You may display or store the road name for the trip in your database.

In the sample we have set up a road layer; when you click on the map it will find the closest road segment within a tolerance and snap the point to that road. You can click repeatedly around a road and simulate GPS points coming in. Inside of the sample, we have encapsulated the functionality into a method that can easily support multiple layers, varying tolerances, and different data units.