问题
I'm using a combination of alarm (set with AlarmManager) and background service to periodically synchronize data in my application.
The only problem I have is that when sleep policy terminates Wi-Fi connection the synchronization no longer works.
Is there a way to "wake up" the Wi-Fi connection that has been put to sleep? GMail somehow manages to do that because it notifies me about new e-mail even if the phone entered sleep mode.
回答1:
[update]You can use a WifiLock to keep WiFi active, while holding the lock.
Using an AlarmManager and a Service says to me your service is running only for a very short time!? I think (though can't say for certain) that you should make your service a forground service (check the blog for a good way to implement this on both 1.x and 2.x+) and leave the AlarmManager out of it.
来源：https://stackoverflow.com/questions/2487008/network-access-when-the-android-phone-is-asleep