Activity can't start from broadcast receiver

Question

Start Activity from Broadcast receiver is not working on android 9 but its working below android 9 it's working fine, I searched a lot regarding this but could not find the suitable solution. Does anyone face the same problem, here is my code.

public void onReceive(final Context context, Intent intent) {

    try {
        this.tm = (TelephonyManager) context.getSystemService("phone");
        this.tm.listen(new PhoneStateListener() {
            public void onCallStateChanged(int state, final String num) {
                if (state == 1 && Receiver.this.preferences.getInt("start", 0) == 1) {
                    try {
                        new Handler().postDelayed(new Runnable() {
                            public void run() {
                                Receiver.this.i = new Intent(context, MainActivity.class);

                                context.startActivity(Receiver.this.i);
                            }
                        }, 300);
                    } catch (Exception e) {

                    }
                } 

Answer 1

you need to add flag to the intent

i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

before you call context.startActivity(i);

Answer 2

Android Q (API level 29) and higher place restrictions on when apps can start activities when the app is running in the background.

https://developer.android.com/guide/components/activities/background-starts

However, you can achieve this by giving alert window permission.

How to start a activity from a broadcast receiver when the screen is locked in Android Q

It is working like a charm

Answer 3

Add this in your AndroidManifest.xml

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>

Ask for display overlay permission from appropriate activity:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    if(! Settings.canDrawOverlays(context)) {
        Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION, Uri.parse("package:" + context.getPackageName()));
        startActivityForResult(intent, 101);
    }
}

Handle it inside onActivityResult:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == 101) {

            if(!Settings.canDrawOverlays(context)) {
                Toast.makeText(context, "This feature is crucial to this app", Toast.LENGTH_SHORT).show();
            }
        }
}

In your BroadcastReceiver implementation:

@Override
public void onReceive(Context context, Intent intent) {
    Intent intent1 = new Intent(context, ToBeOpenedActivity.class);
    intent1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(intent1);
}

Answer 4

Below I send on example for starting activity from the broadcast receiver, But this one is for starting the MainActivity after device reboot.

public class StartReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action= intent.getAction();
        if( action.equals("android.intent.action.BOOT_COMPLETED") ){

            Intent i= new Intent(context, MainActivity.class);
            i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

            context.startActivity(i);
        }
    }

}

Answer 5

I see that you're listening to onCallStateChanged. But I think you need to ask permission for that on Android 9: https://stackoverflow.com/a/52025013/2212770