使用 copyToRealmOrUpdate 时列表未完全加载

Question

我从 API 调用中获取多个对象，并尝试将它们显示到 ListView 中。

代码如下

public class ExerciseActivity extends AppCompatActivity {

private CompositeDisposable disposables = new CompositeDisposable();
private ExerciseClient exerciseClient;
private List<Exercise> exerciseList;

private Realm realm;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_exercise);
    exerciseList = new ArrayList<>();

    this.realm = Realm.getDefaultInstance();
    exerciseClient = new ExerciseClient(this);
    populateExerciseList();

}

private void setupExerciseList() {
    ListView lvItems = findViewById(R.id.lvItems);
    ArrayAdapter<Exercise> adapter = new ArrayAdapter<>(this, R.layout.list_view, exerciseList);
    lvItems.setAdapter(adapter);
}


void populateExerciseList() {
    disposables.add(exerciseClient.getExercises()
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(
                    this::getExercisesSuccess,
                    this::getExercisesError
            )
    );
}

private void getExercisesError(Throwable throwable) {
    exerciseList = realm.where(Exercise.class).findAll();
    setupExerciseList();

}

private void getExercisesSuccess(List<Exercise> exercises) {
    this.realm.executeTransaction(realm -> realm.where(Exercise.class).findAll().deleteAllFromRealm());
    for (int i = 0; i < exercises.size(); i++) {
        Exercise foundExercise = exercises.get(i);
        this.exerciseList.add(foundExercise);
        this.realm.executeTransactionAsync(realm -> realm.copyToRealmOrUpdate(foundExercise));

    }
    setupExerciseList();
}

列表只会加载 0 到 3-4 个元素，如果我评论 this.realm.executeTransactionAsync(realm -> realm.copyToRealmOrUpdate(foundExercise)); 行，列表会按预期加载。

请记住，我必须从 API 收集 1000 个对象。

我的猜测是 this.realm.executeTransactionAsync(realm -> realm.copyToRealmOrUpdate(foundExercise)); 的计算时间太长，因此在应用启动时我只得到

是否有任何可能的解决方法？

编辑：另外，我已经从数据库中删除了一些条目，只删除了大约 50 个条目，即使存在该行，它现在似乎也可以工作，所以问题肯定是大量数据。

Answer 1

怎么样

public class ExerciseActivity extends AppCompatActivity {

    private CompositeDisposable disposables = new CompositeDisposable();
    private ExerciseClient exerciseClient;

    private Realm realm;
    private RealmResults<Exercise> results;
    private RealmBaseAdapter<Exercise> adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_exercise);
        exerciseList = new ArrayList<>();

        this.realm = Realm.getDefaultInstance();
        this.results = realm.where(Exercise.class).findAllAsync();
        this.adapter = new RealmBaseAdapter<Exercise>(results);
        exerciseClient = new ExerciseClient(this);
        populateExerciseList();

        ListView lvItems = findViewById(R.id.lvItems);
        lvItems.setAdapter(adapter);
    }

    void populateExerciseList() {
        disposables.add(exerciseClient.getExercises()
                .subscribeOn(Schedulers.io())
                .subscribe(
                        this::getExercisesSuccess,
                        this::getExercisesError
                )
        );
    }

    private void getExercisesError(Throwable throwable) {
        runOnUiThread(() -> {
            // d'oh
        });
    }

    private void getExercisesSuccess(List<Exercise> exercises) {
        try(Realm r = Realm.getDefaultInstance()) {
            r.executeTransaction(realm -> {                     
               realm.where(Exercise.class).findAll()
                       .deleteAllFromRealm();
                for(Exercise exercise: exercises) {
                    realm.insertOrUpdate(exercise);
                }
            });
        }
    }
}