CODEWITHSUNDEEP
androidandroid-fragmentsback-stack
Artyom Okun
Artyom Okun

Reputation: 985

Adding Fragments to backstack

I am trying to manage Fragments on single activity by switching them when radio buttons are pressed. On each replace operation I am calling addToBackStack() method but when I pressing back button it closes the activity instead going to previous fragment.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_flow);
    radioGroup = (RadioGroup) findViewById(R.id.rdoGrp);
    rdBtnHome = (RadioButton) findViewById(R.id.rdBtnHome);
    rdBtnSearch = (RadioButton) findViewById(R.id.rdBtnSearch);
    rdBtnShoot = (RadioButton) findViewById(R.id.rdBtnShoot);
    rdBtnUser = (RadioButton) findViewById(R.id.rdBtnUser);
    rdBtnAlarm = (RadioButton) findViewById(R.id.rdBtnAlarm);
    homeFragment = new HomeFragment();
    searchFragment = new SearchFragment();
    userFragment = new UserFragment();
    shootFragment = new ShootFragment();
    alarmFragment = new AlarmFragment();


 getSupportActionBar().setDisplayOptions(android.support.v7.app.ActionBar.DISPLAY_SHOW_CUSTOM);
    getSupportActionBar().setCustomView(R.layout.actionbar);

    FragmentManager fm = getFragmentManager();
    FragmentTransaction ft = fm.beginTransaction();
    ft.replace(R.id.frameLayoutMain, homeFragment);
    ft.addToBackStack(null);
    ft.commit();

    rdBtnHome.setChecked(true);


    // Creating once image loader configuration
    createImageLoaderConfiguration();

    // Defining footer radiogroup including radiogroup callback listener
    defineFooterRadioGroup();

    Log.d("Logged User", Me.meGetInstance().toString());
}


private void defineFooterRadioGroup() {


    radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            FragmentManager fm = getFragmentManager();
            FragmentTransaction ft = fm.beginTransaction();
            switch (checkedId) {
                case R.id.rdBtnHome:
                    ft.replace(R.id.frameLayoutMain, homeFragment);
                    ft.addToBackStack(null);
                    ft.commit();
                    break;
                case R.id.rdBtnAlarm:
                    ft.replace(R.id.frameLayoutMain, alarmFragment);
                    ft.addToBackStack(null);
                    ft.commit();
                    break;
                case R.id.rdBtnSearch:
                    ft.replace(R.id.frameLayoutMain, searchFragment);
                    ft.addToBackStack(null);
                    ft.commit();
                    break;
                case R.id.rdBtnShoot:
                    ft.replace(R.id.frameLayoutMain, shootFragment);
                    ft.addToBackStack(null);
                    ft.commit();
                    break;
                case R.id.rdBtnUser:
                    ft.replace(R.id.frameLayoutMain, userFragment);
                    ft.addToBackStack(null);
                    ft.commit();
                    break;
            }

        }
    });

}

Upvotes: 0

Views: 1319

Answers (3)

georgeok
georgeok

Reputation: 5696

Here is a way to remove a fragment with code inside the fragment.

public void removeMe() {
    FragmentTransaction ft = getFragmentManager().beginTransaction();
    Fragment prevHistory = getFragmentManager()
            .findFragmentByTag("LOG_IN");
    if (prevHistory != null) {
        ft.remove(prevHistory);
    }
    ft.commit();

}

You need to call the removeMe method. So add a key listener to the back button.

view.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if(keyCode==KeyEvent.KEYCODE_BACK){
                removeMe();
            }
            return true;
        }
    });

The view can be anything. If you want a global solution, the view is the fragment's view.

To make this method work you need to add a tag to the fragment transaction when you add or replace a fragment.

Fragment newFragment = new Fragment();
            ft.replace(R.id.fragment_container, newFragment, "The fragment tag goes here");

Upvotes: 0

iMDroid
iMDroid

Reputation: 2128

Added popBackStack() to your Activity's BackPressed Listener like this..

 if (getSupportFragmentManager().getBackStackEntryCount() > 0) {

     getSupportFragmentManager().popBackStack();
 }

Upvotes: 2

QuokMoon
QuokMoon

Reputation: 4425

  1. You should override onBackPress() method into your activity .
  2. You will get a fragment from stack and you can retrive this value from method is "getBackStackEntryCount();".
  3. Check size of your stack before exit from application.

Upvotes: 0

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