如何动态更改底部导航项文本？

Question

Im trying to achieve the above design. I'm able to change the icons, but cannot change the bottom text. Im using material bottom navigation bar

I achieved the icon change by implementing separate selector drawables for each icon. Is there any way that i can do the same with the nav titles?

MainActivity.class

public class MainActivity extends AppCompatActivity {
BottomNavigationView navView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    navView = findViewById(R.id.nav_view);

    // Passing each menu ID as a set of Ids because each
    // menu should be considered as top level destinations.
    AppBarConfiguration appBarConfiguration = new AppBarConfiguration.Builder(
            R.id.navigation_home, R.id.navigation_saved, R.id.navigation_applied, R.id.navigation_profile, R.id.navigation_more)
            .build();

    NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
    NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);
    NavigationUI.setupWithNavController(navView, navController);



}

activity_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"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingTop="?attr/actionBarSize">

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/nav_view"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="0dp"
        android:layout_marginEnd="0dp"
        app:itemIconTint="@null"
        app:itemHorizontalTranslationEnabled="false"
        android:background="?android:attr/windowBackground"
        app:layout_constraintBottom_toBottomOf="parent"
        app:labelVisibilityMode="labeled"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:menu="@menu/bottom_nav_menu" />

    <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_constraintBottom_toTopOf="@id/nav_view"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:navGraph="@navigation/mobile_navigation" />

</androidx.constraintlayout.widget.ConstraintLayout>

bottom_nav_menu.xml

    <item
        android:id="@+id/navigation_home"
        android:icon="@drawable/home_selector"
        android:title="@string/title_home" />

    <item
        android:id="@+id/navigation_saved"
        android:icon="@drawable/saved_jobs_selector"
        android:title="@string/title_saved" />

    <item
        android:id="@+id/navigation_applied"
        android:icon="@drawable/applied_jobs_selector"
        android:title="@string/title_applied" />

    <item
        android:id="@+id/navigation_profile"
        android:icon="@drawable/profile_selector"
        android:title="@string/title_profile" />


    <item
        android:id="@+id/navigation_more"
        android:icon="@drawable/more_selector"
        android:title="@string/title_More" />

</menu>

Answer 1

Hi I could change the title in the navigation bar by implementing:

private BottomNavigationView.OnNavigationItemSelectedListener navListener = new BottomNavigationView.OnNavigationItemSelectedListener() {
    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item)
    {
        switch (item.getItemId())
        {
            
        }
    }
};

After it in the switch you add the string based on the item id

Answer 2

You can change like this:

for(i in 0 until bottomNavigation.maxItemCount){
   bottomNavigation.menu[i].title = "My Custom Title"
}

Answer 3

I change the title and Icon programmatically like that:

fun changeMenuItemTextAndIcon(){
    val item: MenuItem = bottom_navigation.menu.findItem(R.id.action_scan)
    item.title = getString(R.string.label_scan_item)
    item.icon = ContextCompat.getDrawable(activity, R.drawable.ic_barcode)
}

Answer 4

检查代码行下方，并在您在 Kotlin 中选择 BottomNavigation 项时添加它（将 java 转换为 kotlin ）。

navView.getCheckedItem().setTitle(".");