Invoking a Service

Services can be used by any application component that “hangs around” for a reasonable period of time. This includes activities, content providers, and other services. Notably, it does not include pure intent receivers (i.e., intent receivers that are not part of an activity), since those will get garbage collected immediately after each instance processes one incoming .

To use a service, you need to get an instance of the AIDL interface for the service, then call methods on that interface as if it were a local object. When done, you can release the interface, indicating you no longer need the service.

In this chapter, we will look at the client side of the sample application. The activity looks an awful lot like the original Weather application – just a Web page showing a weather forecast as you can see in Figure 31‑1.

Figure 31‑1. The WeatherPlus service client

The difference is that, as the emulator “moves”, the weather forecast changes, based on updates provided by the service.