Update NavigationView state when user goes back to previous fragment

Question

I'm using the NavigationView drawer in my app. I'm trying go back to the previous Fragment if the user press back button. This code works well:

@Override
public void onBackPressed() {
    FragmentManager fm = getSupportFragmentManager();        
    Fragment fr = fm.findFragmentById(R.id.flContent);

    if (fm.getBackStackEntryCount() > 0 ) {
        fm.popBackStackImmediate();
    }
    else {
        finish();
    }        
}

But my NavigationView doesn't change. How can I update the NavigationView state (check the correct fragment, change title, and so on), so it can reflect the changes in my app?

score 0 · Answer 1 · answered Jul 27 '15 at 13:00

0

You should implement Back Navigation using addToBackStack method. Take a look at this.

answered Jul 27 '15 at 13:00

user3641702

393
1
5
18

This answers only the question when to update. I could also use onBackPressed(). The main question is which position should be highlighted in the drawer? – aseolin Jul 27 '15 at 13:53
check the first answer [link](http://stackoverflow.com/questions/18305945/how-to-resume-fragment-from-backstack-if-exists) – user3641702 Jul 27 '15 at 14:25

score 0 · Answer 2 · answered Jul 27 '15 at 14:54

I created a workaround: When drawer is created or menuItem is clicked, I'm storing the current menuItem:

private void setupDrawerContent(NavigationView navigationView) {
    // Storing "home" menuItem when app starts
    storedMenuItem = navigationView.getMenu().getItem(0);

    navigationView.setNavigationItemSelectedListener(
            new NavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(MenuItem menuItem) {
                    selectDrawerItem(menuItem);

                    // Storing menuItem when another item is selected
                    storedMenuItem = menuItem;

                    return true;
                }
            });
}

So in my onBackPressed method I'm doing this:

  @Override
  public void onBackPressed() {
    selectDrawerItem(storedMenuItem);
  }

No changes on selectDrawerItem (I used this code)

I don't know if it's a good solution, but it's working very well.

this works only for first back, if i open 3 menuitem and then press 2 times back doesen't works — Alessandro Scarozza, Feb 29 '16 at 10:56

Update NavigationView state when user goes back to previous fragment

2 Answers2