broadcast receiver

基本解释

A broadcast receiver is a component that responds to system-wide broadcast announcements.
一个broadcast receiver是响应全系统广播通知的一个组件。
A broadcast receiver is implemented as a subclass of BroadcastReceiver and each broadcast is delivered as an Intent object.
一个broadcast receiver通过继承BroadcastReceiver类来实现，每个broadcast被作为一个Intent对象发布。
More commonly, though, a broadcast receiver is just a "gateway" to other components and is intended to do a very minimal amount of work.
但是，更常见的情况是，broadcast receiver只作为其他组件的“出入口”(gateway)，其本身做的工作非常少。