按下后退按钮时清除包装

Question

I use fragments (ListFragment) in an activity and i save the selected item to restore it when the screen rotates.

@Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("currentListIndex", mCurrentSelectedItemIndex);
    }

When the user clicks on "back" I don't want to save the item selection. I need to override the back button and clear the bundle instance passed to my activity.

I don't really know how to get the bundle instance, I've tried to use a global var but when I use it i have a NullPointerException.

Here is how i do :

private Bundle bundle;

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
        bundle.clear();
    } 

    return super.onKeyDown(keyCode, event);
}

Where can i retrieve the information I want (currentListIndex): in the onCreate() of my activity / onCreateView() of my detail fragment ?

Answer 1

ok I have found the solution.

In my class that extends ListFragment :

// Restore last state for checked position (when screen orientation
        // change or activity resumed)
        if (savedInstanceState != null) {
            mCurrentSelectedItemIndex = savedInstanceState.getInt(
                    "currentListIndex", -1);
        }

In my activity :

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    AccountBDD accountBdd = application.getAccountBdd();
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
        mCurrentSelectedItemIndex = -1;
    }
    return super.onKeyDown(keyCode, event);
}

and it works