第一个片段被第二个片段替换后，如何打开导航抽屉

Question

我已经创建了默认的Android Studio导航抽屉项目。默认情况下，我有一个活动和三个主要片段。（家庭，画廊，幻灯片），我只是尝试与家庭片段。我已经将 从content_main XML替换为

<androidx.fragment.app.FragmentContainerView
    android:id="@+id/nav_host_fragment_content_main"
    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" /> 

并将MainActivity修改为

//inside onCreate
NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.nav_host_fragment_content_main);

    NavController navController;
    if (navHostFragment != null) {
        navController = navHostFragment.getNavController();
        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, navController);
    } else {
        Log.e("Error", "Failed on NULL NavController");
    }

@Override
public boolean onSupportNavigateUp() {
    NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.nav_host_fragment_content_main);
    assert navHostFragment != null;
    return NavigationUI.navigateUp(navHostFragment.getNavController(), mAppBarConfiguration)
            || super.onSupportNavigateUp();
}

binding.button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Log.d("onClick: ", "Clicked");
            BlankFragment blankFragment = new BlankFragment();
            requireActivity().getSupportFragmentManager().beginTransaction()
                    .replace(R.id.nav_host_fragment_content_main, blankFragment, null)
                    .addToBackStack("blank").commit();
        }
    });

java.lang.ClassCastException: BlankFragment cannot be cast to androidx.navigation.fragment.NavHostFragment

Answer 1

正如Zain在评论中建议的那样，我尝试使用NavController。试了下面的，它似乎工作，为其他人张贴。https://learntodroid.com/how-to-move-better-fragments-using-the-navigation-component/