Question

I have written an activity A, when users press a button, it will do MyConfig.doSomething() where MyConfig is simple class with activity A passed to it.

public class A extends PreferenceActivity {
    private MyConfig mMyConfig;

    /* pseudo code, when button clicked, call */        
    mMyConfig.doSomething();
}

In mMyConfig, it accesses SharedPreferences for some configuration. Thus, I can do this to pass the activity to mMyConfig for calling getSharedPreferences().

mMyConfig = new MyConfig ( this );

Here comes my request:

I want to do something that MyConfig.doSomething() already does, but except when users click some button to invoke it, I want to invoke it when Android Boots-Up.

I can write another class to extend BroadcastReceiver and then starts activity A by calling startActivity(A.class), and then in A, do some tricks to make mMyConfig.doSomething() happen. It works but the Application will be shown on screen when Android Boots-Up.

I want to make mMyConfig.doSomething() happen implicitly without letting users be aware of it. I suppose two possible solutions but I don’t know how to do it.

Solution A:
Write a class that extends BroadcastReceiver, start a service (instead of activity A) that reads the SharedPreferences of A and create MyConfig object to do doSomething(). However, I don’t if this can work if activity itself is never launched and how could I do this (read SharedPreferences from a service)?

Solution B:
Write a class that extends BroadcastReceiver, start activity A without showing it, put it to activity stack by calling startActivity(A.class) in onReceive. Is this possible?

Answer 1

Instead of Activity, which are meant to be visible to the user, you can make your BoardcastReceiver to start a Service instead. It is meant to perform tasks in the background without disturbing the user. The official guide is a nice place to start with.

Edited:

To access the SharedPreference of your application, simply call this line inside your service:

SharedPreferences pref = PreferenceManager.getSharedPreferences();