How i can use SharedPrefs when catching "BOOT_COMPLETED" on Android?

Question

I'm writing an android application. In this application, the user can type text which I then send to a notification to show up to the user. I store the text as strings in the sharedpreferences. The notifications are triggered by an alarmmanage which is switched off if the phone is switched off. When the phone restarts my StartUpReceiver catches the "BOOT_COMPLETED" broadcast and sends a notification. The problem is, the notification cannot use the sharedpreferences strings to show the users textinput.

I found out, that the application has to run in fore- or background to use sharedpreferences. So i am now thinking, if my StartUpReceiver turns on, its just him, and not my application tuning on, right? So it is not possible to use sharedpreferences on the StartUpReceiver? Or is there any method u know?

My other solution (but i did not practice them yet) is, to start a service (internet says i can use shared prefs there) and let the service send the notification.

But in newer Android the service has to be a foreground service, and I really don't like that way of solution. So if u have any other solution, i would appreciate it.

At last, sorry for my bad English. But I hope u understood what I wanted to say. :-)

Thank you very much!

Answer 1

I am not sure why you would not be able to use SharedPreferences inside your Receiver. Here is how I do it in my app.

1. In the AndroidManifest.xml I register my BroadcastReceiver like this:

<receiver
        android:name=".data.receiver.AlarmBootReceiver"
        android:enabled="true">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
        </intent-filter>
</receiver>

2. I create a class called AlarmBootReceiver that looks like this:

class AlarmBootReceiver : BroadcastReceiver() {

    override fun onReceive(context: Context, intent: Intent) {
        if (intent.action == "android.intent.action.BOOT_COMPLETED") {
            // You can obtain SharedPreferences here (you have a Context as a parameter)
        }
    }
}

3. Now, inside the onReceive() method you can register your notifications by passing any data that you need via Intent.