摘要：
1.Services A Service is an application component that can perform long-running operations in the background and does not provide a user interface. A... 阅读全文
摘要：
1. Tasks and Back Stack An application usually contains multiple activities. Each activity should be designed around a specific kind of action the us... 阅读全文
摘要：
1. Loaders loaders make it easy to asynchronously load data in an activity or fragment. Loaders have these characteristics: They are available to ... 阅读全文