按照說明實現 Java 代碼后，當我選擇導航抽屜上的課程項目時，它仍然顯示與注釋項目相同的內容。請幫忙? ? ? ? mNoteLayoutManager = new LinearLayoutManager(this);? ? ? ? mCoursesLayoutManager = new GridLayoutManager(this, 2);? ? ? ? List<NoteInfo> notes = DataManager.getInstance().getNotes();? ? ? ? mNoteRecyclerAdapter = new NoteRecyclerAdapter(this, notes);? ? ? ? List<CourseInfo> courses = DataManager.getInstance().getCourses();? ? ? ? mCourseRecyclerAdapter = new CourseRecyclerAdapter(this, courses);? ? ? ? displayNotes();?public boolean onNavigationItemSelected(MenuItem item) {? ? ? ? // Handle navigation view item clicks here.? ? ? ? int id = item.getItemId();? ? ? ? if (id == R.id.nav_notes) {? ? ? ? ? ? displayNotes();? ? ? ? } else if (id == R.id.nav_courses) {? ? ? ? ? ? displayCourses();? ? ? ? } else if (id == R.id.nav_share) {? ? ? ? ? ? handleSelection("Don't you think you've shared enough");? ? ? ? } else if (id == R.id.nav_send) {? ? ? ? ? ? handleSelection("Send");? ? ? ? }? ? ? ? DrawerLayout drawer = findViewById(R.id.drawer_layout);? ? ? ? drawer.closeDrawer(GravityCompat.START);? ? ? ? return true;? ? }? @Override? ? protected void onCreate(Bundle savedInstanceState) {? ? ? ? super.onCreate(savedInstanceState);? ? ? ? setContentView(R.layout.activity_main2);? ? ? ? Toolbar toolbar = findViewById(R.id.toolbar);? ? ? ? setSupportActionBar(toolbar);? ? ? ? FloatingActionButton fab = findViewById(R.id.fab);? ? ? ? fab.setOnClickListener(new View.OnClickListener() {? ? ? ? ? ? @Override? ? ? ? ? ? public void onClick(View view) {? ? ? ? ? ? ? ? startActivity(new Intent(MainActivity.this, NoteActivity.class));? ? ? ? ? ? }? ? ? ? });