Android:导航组件不能同时使用: 和 NavigationItemSelectedListener

Question

我做了什么:

我创建了Navigation Drawer Activity，更新了Navigation Drawer Activity的新格式，根据新的Android架构，我用 Navigation Component得到了它结构。

NavigationView代码 NavController和 NavigationUI如下所示，当我点击任何导航项时打开 fragment 。

    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_profile, R.id.nav_privacy_policy,
            R.id.nav_terms, R.id.nav_contact_us, R.id.nav_share, R.id.nav_send)
            .setDrawerLayout(drawer)
            .build();
    NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
    NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
    NavigationUI.setupWithNavController(navigationView, navController);

这是给 nav_host_fragment 的:

<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" />

导航正在使用这个 navigation/mobile_navigation.xml 进行

<?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.sohamerp.marsremedies.fragment.HomeFragment"
        android:label="@string/menu_home"
        tools:layout="@layout/fragment_home" />

    <fragment
        android:id="@+id/nav_profile"
        android:name="com.sohamerp.marsremedies.fragment.ProfileFragment"
        android:label="@string/menu_my_profile"
        tools:layout="@layout/fragment_profile" />

    <fragment
        android:id="@+id/nav_privacy_policy"
        android:name="com.sohamerp.marsremedies.fragment.PrivacyPolicyFragment"
        android:label="@string/menu_privacy_policy"
        tools:layout="@layout/fragment_privacy_policy" />

    <fragment
        android:id="@+id/nav_terms"
        android:name="com.sohamerp.marsremedies.fragment.TermsConditionFragment"
        android:label="@string/menu_terms"
        tools:layout="@layout/fragment_terms_condition" />

    <fragment
        android:id="@+id/nav_contact_us"
        android:name="com.sohamerp.marsremedies.fragment.ContactUsFragment"
        android:label="@string/menu_contact_us"
        tools:layout="@layout/fragment_terms_condition" />

</navigation>

我遇到问题的地方:

Android Studio 已为所有 6 个菜单创建 fragment ，但我不想在单击最后两项时打开 fragment 。 为此，我删除了最后两个 <fragment>来自 mobile_navigation.xml 的标签

我尝试添加下面的 setNavigationItemSelectedListener。

    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
            if (menuItem.getItemId() == R.id.nav_share)
                Toast.makeText(NavigationMenuActivity.this, "Sharing...", Toast.LENGTH_SHORT).show();
            else if (menuItem.getItemId() == R.id.nav_send)
                Toast.makeText(NavigationMenuActivity.this, "Rating...", Toast.LENGTH_SHORT).show();
            return false;
        }
    });

当我点击最后两个菜单但前 4 个菜单不起作用时，Toast 正在显示。

我该怎么做才能让它发挥作用？

build.gradle 依赖:

implementation 'androidx.navigation:navigation-fragment:2.1.0'
implementation 'androidx.navigation:navigation-ui:2.1.0'
implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'

Answer 1

您可以创建一个 switch 语句，对于其他 4 个 fragment 您应该返回 true。

    switch(menuItem.getItemId) {
      case R.id.import:
          navController.navigate(R.id.nav_home)
          return true
      case R.id.nav_gallery:
          navController.navigate(R.id.nav_gallery)
          return true
      case R.id.nav_slideshow:
          navController.navigate(R.id.nav_slideshow)
          return true
      case R.id.nav_tools:
          navController.navigate(R.id.nav_tools)
          return true
      case R.id.nav_share:
                Toast.makeText(NavigationMenuActivity.this, "Sharing...", Toast.LENGTH_SHORT).show();
          return false;
  case R.id.nav_send: 
                Toast.makeText(NavigationMenuActivity.this, "Rating...",Toast.LENGTH_SHORT).show();
          return false;
      default:
          return false;
}
}

通过重写 onBackPressed，您可以实现默认行为。 (注意:默认行为只是返回到第一个 fragment ，然后在其关闭 Activity 之后)

public void onBackPressed() {

 if (navigationDrawer.isDrawerOpen(GravityCompat.START)) {
            navigationDrawer.closeDrawer(GravityCompat.START)
    } else {
          if (navController.currentDestination?.id == R.id.nav_home){
              finish()
          } else {
           navController.navigate(R.id.action_global_nav_home)
           drawerView.menu.findItem(R.id.menu_item_nav_home).isChecked = true
          }

并在 navigation/mobile_navigation.xml 中添加一个全局操作:

 <action
        android:id="@+id/action_global_nav_home"
        app:destination="@id/nav_home" />