如何设置导航片段

Question

在我的应用程序中，我有一个导航抽屉，它基本上是主要活动，在此活动中，我还实现了Firebase UI recyclerView。当我在recyclerView中按下某个项目时，它会打开另一个活动（该项目的详细信息），而当我按下时，它会将我带到默认片段。

如何返回导航抽屉中的最后一个片段？

这是导航抽屉和详细信息活动的代码

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_custom_recycleview);
    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    drawer = findViewById(R.id.drawer_layout);
    NavigationView navigationView = findViewById(R.id.nav_view);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open,                    
    R.string.navigation_drawer_close);
    drawer.addDrawerListener(toggle);
    toggle.syncState();
    navigationView.setNavigationItemSelectedListener(this);
    recyclerView = findViewById(R.id.recycler_view);

    if (savedInstanceState == null) {
          getSupportFragmentManager().beginTransaction().replace(R.id.frameLayout,     new TodolistFragment()).commit();
         navigationView.setCheckedItem(R.id.nav_todo_list);


    FloatingActionButton addBtn = findViewById(R.id.fab);

        addBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(CustomRecycleview.this, AddTodoActivity.class);
            startActivity(intent);
        }
    });

}



@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
    switch (menuItem.getItemId()) {
        case R.id.nav_todo_list:
            getSupportFragmentManager().beginTransaction().replace(R.id.frameLayout, new TodolistFragment()).commit();
            break;
        case R.id.nav_todo_updated:
            getSupportFragmentManager().beginTransaction().replace(R.id.frameLayout, new TodoUpdatedFragment()).commit();
            break;
        case R.id.nav_favorite:
            getSupportFragmentManager().beginTransaction().replace(R.id.frameLayout, new TodolistFragment()).commit();
            break;
    }
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@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 onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

}