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androidandroid-fragmentsonbackpressed

fragment back goes to specified fragment


I am developing an android app using fragments. I have five fragments. Those are A,B,C,D,E . My first fragment A is the main fragment. First I traverse from A to B then from B to C. In C when I press back button I want it to go back to A. I have used the below code for calling B fragment from A. This same method is used for calling another fragments.

FragmentB fragment = new FragmentB();
FragmentManager manager = getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction().addToBackStack("tag");
transaction.replace(R.id.content_frame, fragment);
transaction.commit();

The back button code in the activity is as following

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }

}

How to solve this issue please help me.


Solution

  • You can try this:

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        }    FragmentManager fragmentManager = getSupportFragmentManager();
        int backCount = fragmentManager.getBackStackEntryCount();
        System.out.println("back count " + backCount);
    
        if(backCount==0)
        {
            actionBar.setTitle("Home");
           //Here you can show alert dialog for exit the app?
        }
      /*  else if(backCount==1)
        {
    
        }*/
        else if(backCount==1)
        {
            fragmentManager.popBackStack();
            // setTitle("Home");
            navigationView.getMenu().getItem(0).setChecked(true);
            actionBar.setTitle("Home");
        }
        else if(backCount>1)
        {
    
            for(int i=fragmentManager.getBackStackEntryCount();i>=1;i--)
            {
                fragmentManager.popBackStack();
                System.out.println("back count loop" + fragmentManager.getBackStackEntryCount());
            }
            actionBar.setTitle("Home");
        }
    }