Question

我从API调用中获取多个对象，并且我试图将它们显示到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中收集1000个对象。

我的猜测是this.realm.executeTransactionAsync(realm -> realm.copyToRealmOrUpdate(foundExercise));需要太长的时间来计算，因此在应用程序启动时我只能得到＆lt; 5个条目。

有没有可行的解决方法？

编辑：另外，我已经将数据库中的一些条目删除到只有~50，现在它甚至可以使用该行，所以问题绝对是大块数据。

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);
                }
            });
        }
    }
}

当我使用copyToRealmOrUpdate

1 个答案: