问题
I am planning to write an app whose sole purpose will be to monitor the battery level, and launch an intent the moment it drops below a certain level. My one concern is that this itself will be a battery drain, and no one will want to use it.
So my question is: Exactly how much power is drained by using the ACTION_BATTERY_CHANGED broadcast receiver? Does anyone know approximately how much battery life we're talking about?
回答1:
I don't think you'll drain much power. This broadcast is sent only when level changes by one percent,
For example: 85% -> 86% or 76% -> 75%.
Android OS already tracks battery level (it has to track it in order to shutdown phone when level becomes too low, ~3-5%). So just subscribing to this broadcast shouldn't even be noticeable to the user (in terms of battery performance).
来源：https://stackoverflow.com/questions/6239809/exactly-how-much-power-is-drained-by-registering-a-broadcast-receiver-for-action