Question

Please help me this question.
Example I have Activity class MyActivity. I start this Activity and call this instance is “Home”. In this activity I have three button.
called : Button1, Button2, Button3.
When I click on one button, it will start another instance of MyActivity.
So, Could I do like this :

I click on Button1 start A1 , click on Button2 start A2, and then Button3 start A3. We will have activity stack like this : home ->A1 ->A2->A3.
On Activity A3(an instance of MyActivity). When I click on Button1 could I move A1 to front instead of create new one ?
I wonder could I do that ?

Answer 1

If A1, A2 and A3 are all instances of MyActivity you cannot do this because there is no way to tell Android which instance of MyActivity you want to bring to the front.

However, if you create 3 new activities (A1, A2 and A3), each of which derive from MyActivity, then you can do this by setting the flag Intent.FLAG_ACTIVITY_REORDER_TO_FRONT when starting these activities.

You will need to have all 4 activities (MyActivity, A1, A2, A3) in the manifest.

You will have something like this:

public class A1 extends MyActivity {
}

public class A2 extends MyActivity {
}

public class A3 extends MyActivity {
}

and in MyActivity, in ‘onClick()when you start an activity (eitherA1,A2orA3`) you do it like this:

Intent intent = new Intent(this, A1.class); // or A2 or A3
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(intent);