粘性广播已被弃用。文档说:
This method was deprecated in API level 21. Sticky broadcasts should not be used.
They provide no security (anyone can access them), no protection (anyone can modify them), and many other problems.
The recommended pattern is to use a non-sticky broadcast to report that something has changed,
**with another mechanism for apps to retrieve the current value whenever desired**.
这种机制的一个可能的例子是什么?我应该采取什么方法?