从另一个片段导航片段，例如导航链接

Question

In the application, I have:

1. One main activity
2. 4 fragments

2.a. Home fragment 2.b. Data fragment 2.c. Picture fragment 2.d. Link fragment

So inside of the home fragment, there are 3 pictures which links to Data, picture and link fragment. There is a NavigationView which also links to the fragment.

Now, I want to add these links to each picture so it can work as a Navigation links and forwards to the same fragment. How to achieve that?

Currently, I am using setOnClickListener inside home fragment to forward each fragment but I believe there are better ways to do that? This is because when i use setOnClickListener this does not update the current nav link.

Layout

Answer 1

That is a very common task and Google introduced the Navigation component for such tasks. See https://developer.android.com/guide/navigation/navigation-getting-started for reference.

Some reference code (you also need the navigation graph):

In MainActivity

public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      NavController navController = Navigation.findNavController(this, 
      R.id.nav_host_fragment);
    }
}

In MainActivity XML:

<fragment
    android:id="@+id/nav_host_fragment"
    android:name="androidx.navigation.fragment.NavHostFragment"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    app:defaultNavHost="true"
    app:layout_constraintBottom_toTopOf="@+id/bottomNavigationBorder"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:navGraph="@navigation/nav_graph" />

In "onViewCreated" of the navigation Fragment

NavController navController = Navigation.findNavController(view);
btnAction.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
      Bundle bundle = new Bundle();
      bundle.putInt("ACTION", "1");
      navController.navigate(R.id.action_mainFragment_to_nextFragment, bundle);
   }
});

The function navController.navigate() can one or two arguments. The bundle is optional and is used if you want to send information to the target fragment. The "R.id....." attribute is defined in the navigation graph and describes the link between two fragments / activities.

Hope this helps.