How to make ContentObserver work without having application opened?

问题

I need to have my application listen for changes in addressbook in Android. I have read that it can be done using ContentObserver and listening for changes in ContactsContract.Contacts. It seems the lifecycle of the ContentObserver ends when the application is closed.

How do I make the ContentObserver work even if the application wasn't opened?

回答1:

How do I make the ContentObserver work even if the application wasn't opened?

That is not possible. The point behind a ContentObserver is to be notified of changes that might affect a running app, such as changes to data that need to be reflected in an activity showing that data. If your app is not running, you cannot have a ContentObserver.

回答2:

register your Content Observer in the OnStartCommand with return START_STICKY; instead of registering it in the onCreate. It works for me.

@Override  
public int onStartCommand(Intent intent, int flags, int startId) {  
    getContentResolver().registerContentObserver(uri,true, new SMSObserver(new Handler(), getBaseContext())); 
    return START_STICKY;    
} 

来源：https://stackoverflow.com/questions/19249566/how-to-make-contentobserver-work-without-having-application-opened