问题:

How much performance does it costs to broadcast intents? Is it okay to broadcast multiple per second or are intents expensive?

回答1:

Intents are meant to launch different activities within the Android OS or to inform about basic actions. It seems like a bad design pattern to use them otherwise. As they travel between different processes and therefore implement the Parcelable interface, they are not the most light-weight.

If you are looking to update different activities at the same time you might consider using a common service.

According to this blog post, intents are 10 times slower than direct function calls http://andytsui.wordpress.com/2010/09/14/android-intent-performance/

回答2:

It doesn't cost THAT much, but think of it the same way as you would a broadcast in a network environment. If you want to continually send a message to a device, you wouldn't send broadcasts every 100ms. That would just flood the network. Sending a broadcast once every, say, 10 seconds might be appropriate though.

What exactly the best implementation is entirely depends on what you're doing. In certain circumstances, if you have several services running that need to be run independently, and you're only broadcasting these intents that fast for say, 10 or 15 seconds. That might be ok.

But we can't really say.