CODEWITHSUNDEEP
androidandroid-activity
Dory
Dory

Reputation: 7582

Not to destroy current activity on back button is pressed

I have two activities, A and B. I have a button in A,when pressed starts a new intent to B. However whenever I press the back button while in B, than click the button again is restarts Activity.I do not want to do that,I want it to resume Activity B. Actually I am doing some networking in Activity B and I want to save unless the user wants to refresh. How can I do it? Thanks in advance

Upvotes: 13

Views: 10248

Answers (4)

whotookmyprecious
whotookmyprecious

Reputation: 1

I guess I'm too late but I had a similar problem.

I had two activities A,B and a next button in A.

Whenever I tried to do: A->press next button ->B->press back button->A->press next button->B, B screen got destroyed when I pressed the back button. So when I came back to B for the second time it was a newly created B (all the information I had put in was gone).

So it was like A->B->A->new B when I just wanted to go back to the original B! :(

So what I did was, in activity B, I overrode the onBackPressed() function so it doesn't destroy the activity. I also set the flag so that if there is a A activity already running, it would just pull it up to the front instead of creating a new A activity.

@Override
public void onBackPressed() {
        Intent intent = new Intent(getApplicationContext(), ActivityA.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
        startActivity(intent);
    }

Then, for the onclicklistener function for the next button in activity A, I set the flags similarly.

public void onClickNextbutton(View v){
        Intent intent = new Intent(getApplicationContext(), ActivityB.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
        startActivity(intent);
    }

Upvotes: 0

David Wasser
David Wasser

Reputation: 95578

This sounds like you need to rethink your architecture. You say:

Actually I am doing some networking in Activity B and I want to save unless the user wants to refresh.

If this is the case, you probably don't want to do your networking in ActivityB. Maybe you should start a Service from ActivityB to do the networking. The service and the activity can communicate with each other so that the activity can keep the user up-to-date about the state of the networking. If the user presses BACK in ActivityB, it can finish (as usual) and return to ActivityA. In this case, the Service is still managing the networking. When the user again starts ActivityB (from ActivityA), the new instance of ActivityB can communicate with the service to see if there is any networking going on, and if so it can get the current status of that networking or start it or stop it or whatever.

Upvotes: 1

No_Rulz
No_Rulz

Reputation: 2719

Use

@Override
    public void onBackPressed(){
        moveTaskToBack(true);
    }

Hope, It must help you

Upvotes: 26

Tomer Mor
Tomer Mor

Reputation: 8028

You need to Overrider the

onBackPressed

method and start there the activity like this:

@Override
    public void onBackPressed() {
    Intent intent = new Intent(this, activityA.class);
    startActivityForResult(intent, PICK_CONTACT_REQ);
}

Upvotes: 1

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