Question

I have 3 activities A, B and C.

I inflate activity B dynamically on a button click and the user can add as many views as he likes.

The operation is like this:

User sees “Activity A” first enters his details and clicks the save button and I take him to “Activity B” where he adds certain fields as many times he likes and when he clicks save again I take him to “Activity C”.

Now when I am at A and go to B and add some views and enter text in TextViews and then hit save and go to C. From C if I hit back I see B intact along with all the inflated views and entered text obviously because it is saved in the Back Stack, but if I go from B to A by hitting back and then come back to B all the views are gone because it is removed from the Back Stack.

I wanted to know if it is possible to hold only one instance of B in the BackStack and not kill it at all when the user hits back?
I had overriden back key but to no avail because the activity is killed anyways, some people suggested that I should save the entire views and data from it to a Parcelable ArrayList and regenerate them again in onCreate but that doesnt look feasible to me as I think we can save it in BackStack anyway.

I came across this guide at android developers http://developer.android.com/guide/topics/fundamentals/tasks-and-back-stack.html which says about these activity attributes

android:taskAffinity
android:launchMode
android:allowTaskReparenting
android:clearTaskOnLaunch
android:alwaysRetainTaskState
android:finishOnTaskLaunch
android:singleTask
android:singleInstance

But I am unaware of how to put them to use.

Has anyone tried this out yet? If so please help me put the pieces together.

Answer 1

Yes,I agree with Nandeesh.

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
            switch(keyCode)
            {
            case KeyEvent.KEYCODE_BACK:
                //bring back the previous activity do your logic here           
                return false; //means you don't want to remove the activity from stack 
            }
        return super.onKeyDown(keyCode, event);  // means u want to remove the last activity from Activity stack.
    }

    so question  is that how u can go to other activity without remove it from stack, 
    you can use  :
                Intent myIntent = new Intent(CurrentClass.this, JumptoActivity.class);
                 startActivity(myIntent);*

example: at the switch case u can use this

if(KeyEvent.KEYCODE_BACK)
{
                Intent myIntent = new Intent(CurrentClass.this, NextActivity.class);
                 startActivity(myIntent);
                return false;
}
else
    return true;       //if you not write this then your  menu and other think will be affected.

Thank you I think this little bit information will be helpful for u.