AndroidRX - 在后台运行方法

Question

我创建了带有无限进度条的简单 Activity ，我尝试使用 RxJava 运行耗时的方法来防止 UI 线程阻塞，但每次 UI 线程都被阻塞。我认为我的解决方案在发射 Observable 方面存在问题。谁能帮我？我是 RX 的初学者。

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

public void doSomething(View view) {
    doHeavyStuff()
            .subscribeOn(Schedulers.newThread())
            .observeOn(AndroidSchedulers.mainThread())
            .doOnNext(new Action1() {
                @Override
                public void call(Object o) {
                    Toast.makeText(getApplicationContext(), "FINISHED", Toast.LENGTH_SHORT).show();
                }
            })
            .subscribe();
}

private Observable doHeavyStuff() {
    for (int i = 0; i < 999999999; i++) {
        for (int j = 0; j < 2; j++) {
        }
    }
    return Observable.just(1);

}

Answer 1

对于 RxJava2，一个可能的解决方案是:

带有 lambda 的版本:

Single.fromCallable(() -> loadInBackground())
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe((resultObject) -> { updateUi(resultObject) });

没有 lambda 的版本:

Single.fromCallable(new Callable<Object>() {
    @Override
    public Object call() throws Exception {
        return loadInBackground();
    }
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<Object>() {
    @Override
    public void accept(Object resultObject) throws Exception {
        updateUi(resultObject);
    }
 });

上面使用的示例方法:

private Object loadInBackground() {
    // some heavy load code
    return resultObject;
}

private void updateUi(Object resultObject) {
    // update your Views here
}