@Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    lesson = (Lesson) this.getIntent().getSerializableExtra("data");

    ActionBar actionBar = getSupportActionBar();
    actionBar.setTitle(lesson.getName());

    setContentView(R.layout.activity_lesson_six);
    ButterKnife.bind(this);
    noteDao = new Note_imp();

    btnAdd.setOnClickListener(
        view -> {
          addNote();
        });

    btnSerach.setOnClickListener(
        view -> {
          search(editText.getText().toString());
        });

    // 生成适配器
    sixAdapter = new SixAdapter(this, noteDao.getAllNotes());
    listView.setAdapter(sixAdapter);
    search(null);
  }