我正在構建一個連接到 REST API 并檢索數據庫中所有員工的應用程序。該應用程序使用 RecyclerView 顯示在 CardView 中帶回的所有員工。問題是 RecyclerView 中沒有出現(xiàn)任何內容，并且有從 REST API 返回的數據。它是一個 Android 應用程序，使用 Java 構建，操作系統(tǒng)使用 Pie。該項目是使用基本活動模板創(chuàng)建的。我的活動課public class ViewAllEmployees extends AppCompatActivity {    private List<Employee> employees;    private RecyclerView rcView;    private EmployeeAdapter adapter;    private Context context;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_view_all_employees);        Toolbar toolbar = findViewById(R.id.toolbar);        setSupportActionBar(toolbar);        context = this;        getSupportActionBar().setDisplayHomeAsUpEnabled(true);        FetchEmployeesTask async = new FetchEmployeesTask(new AsyncResponse() {            @Override            public void processFinished(List<Employee> output) {                Log.i("Async", "Finished");            }        });        async.execute();        rcView = findViewById(R.id.rcView);        adapter = new EmployeeAdapter(context, employees);        rcView.setAdapter(adapter);        rcView.setLayoutManager(new LinearLayoutManager(context));    }    private class FetchEmployeesTask extends AsyncTask<Void, Void, List<Employee>> {        public AsyncResponse delegate = null;        public  FetchEmployeesTask(AsyncResponse asyncResponse){            delegate = asyncResponse;        }        @Override        protected List<Employee> doInBackground(Void... voids) {            return new APIHelper().fetchItems();        }        @Override        protected void onPostExecute(List<Employee> items) {            employees = items;            delegate.processFinished(items);        }    }    public interface AsyncResponse{        void processFinished(List<Employee> output);    }