Android. Switch between 2 activities without re-creating and finishing

Question

I have 2 activities "A" and "B". I need to switch between them without finishing and recreating.

Run app -> create and show A -> press button -> create and show B -> press button -> show already exist A -> press button -> show already exist B -> and so on.

Current solution:

private void toA() {
    Intent intentToA = new Intent(this, A.class);
    intentToA.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
    startActivity(intentToA);
}

private void toB() {
    Intent intentToB = new Intent(this, B.class);
    intentToB.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
    startActivity(intentToB);
}

It works on VM (native, Genymotion - android 4.1). Activities will created only once. And when I switch between them, everyting is okay - no calls of the onCreate or onDestroy. It is exactly what I want.

But when I run same app on real device (Nexus 4 - android 4.3) activities are destroyed and recreated while switching.

on VM:

Run app -> 
A: onCreate, onResume -> 
press button -> 
B: onCreate, onResume -> 
press button -> 
A: onResume - > 
press button -> 
B: onResume -> 
...

on Real Device:

Run app -> 
A: onCreate, onResume -> 
press button -> 
B: onCreate, onResume & A: onDestroy ->
press buttom ->
A: onCreate, onResume & B: onDestory ->
...

Note: Intent flag has no effect on the switch behavior.

Answer 1

Set launchMode of Activities to singleInstance in AndroidManifest.xml

Hope this helps.