CODEWITHSUNDEEP
javaandroidandroid-activity
Mike087
Mike087

Reputation: 491

Calling startActivity(new Intent(context, activityA.class) creates another instance of activityA?

Say I have activityA (launcher activity), and from here I start activityB. At this point activityA is on the activity stack. Now from activityB I call startActivity(new Intent(context, activityA.class). My question is: it creates another instance of activityA or recreates activityA?

Upvotes: 4

Views: 858

Answers (4)

David Wasser
David Wasser

Reputation: 95626

To finish B and recreate an instance of A (what you said you wanted to do in the comments), do this:

Intent intent = new Intent(this, A.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
finish();

This will finish B and also finish the existing instance of A, and then create a new instance of A.

Upvotes: 2

androidLearner
androidLearner

Reputation: 1702

If you want to use already existing instance of activity and also want to refresh some data in that activity,you no need to recreate that activity ,instead move that refresh data logic into onStart() because onStart() will invoked first not onCreate() when you use existing instance.

first call finish() method to close activity B and avoid new activityA instance creation.

          @Override
        public void onStart() {
            super.onStart();
            refreshData();
     
    }

//If you can not call refreshData() in onStart(),try below code

Intent intent=new Intent(ActivityA.this,ActivityB.class);
startActivity(intent);
finish(); //this method will clear ActivityA instance from stack.

then create new instance of Activity A from B using intent.

Upvotes: 1

cheese steak jimmy's
cheese steak jimmy's

Reputation: 364

If you want to avoid, that the activityA is launched twice, you can use this flag:

intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

If set in an Intent passed to Context.startActivity(), this flag will cause the launched activity to be brought to the front of its task's history stack if it is already running.

Link to documentation

Upvotes: 1

Paolo Andreuccetti
Paolo Andreuccetti

Reputation: 19

it creates a new instance of activityA.

Upvotes: 1

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