I am trying to apply a lesson I have seen about the Navigation Drawer Activity with Fragments and MVVM "the new Components", in this simple app I have three Fragments I try to navigate between them using
navController.addOnDestinationChangedListener
and show a toast message, but it seems that the code does not work and I do not know the reason
here's the my code
public class MainActivity extends AppCompatActivity {
private AppBarConfiguration mAppBarConfiguration;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = findViewById(R.id.fab);
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction =
fragmentManager.beginTransaction();
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
mAppBarConfiguration = new AppBarConfiguration.Builder(
R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow)
.setDrawerLayout(drawer)
.build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
navController.addOnDestinationChangedListener(new NavController.OnDestinationChangedListener() {
@Override
public void onDestinationChanged(@NonNull NavController controller, @NonNull NavDestination destination, @Nullable Bundle arguments) {
int menuId = destination.getId();
switch (menuId){
case R.id.nav_gallery:
fab.hide();
Toast.makeText(getApplicationContext(),"Gallery",Toast.LENGTH_LONG).show();
fragmentTransaction.replace(R.id.homeFragment,new GalleryFragment());
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
NavGraph navGraph = new NavGraph()
// controller.getGraph().clear();
// controller.navigate(R.id.nav_gallery);
break;
case R.id.nav_slideshow:
fab.hide();
Toast.makeText(getApplicationContext(),"Slideshow",Toast.LENGTH_LONG).show();
break;
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onSupportNavigateUp() {
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
return NavigationUI.navigateUp(navController, mAppBarConfiguration)
|| super.onSupportNavigateUp();
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">
<com.google.android.material.navigation.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_main"
app:menu="@menu/activity_main_drawer" />
<include
layout="@layout/app_bar_main"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</androidx.drawerlayout.widget.DrawerLayout>
content.main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:showIn="@layout/app_bar_main">
<fragment
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="@navigation/mobile_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>
mobile_navigation.xml
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/mobile_navigation"
app:startDestination="@+id/nav_home">
<fragment
android:id="@+id/nav_home"
android:name="com.test.dummyappv3.ui.home.HomeFragment"
android:label="@string/menu_home"
tools:layout="@layout/fragment_home" />
<fragment
android:id="@+id/nav_gallery"
android:name="com.test.dummyappv3.ui.gallery.GalleryFragment"
android:label="@string/menu_gallery"
tools:layout="@layout/fragment_gallery" />
<fragment
android:id="@+id/nav_slideshow"
android:name="com.test.dummyappv3.ui.slideshow.SlideshowFragment"
android:label="@string/menu_slideshow"
tools:layout="@layout/fragment_slideshow" />
</navigation>
while I searching for the solution I found this answer, and I tried to using the controller like this
controller.getGraph().clear();
controller.navigate(R.id.nav_gallery);
instead to using the fragment transaction but it's also not working
question from:
https://stackoverflow.com/questions/65945587/navigate-from-fragment-to-another-using-navcontroller 与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…