Android, RXJava，使用debounce搜索

Question

我使用debounce()来处理用户搜索并处理它在输入时的暂停(在最后一个字符之后搜索1秒):

RxSearchView.queryTextChanges(searchView)
            .debounce(1, TimeUnit.SECONDS)
            .subscribe(new Action1<CharSequence>() {
                @Override
                public void call(CharSequence charSequence) {
                    presenter.loadUsers(charSequence.toString());
                }
            });

所以如果用户删除所有字符，它等待1秒然后加载列表，我如何处理它并立即加载列表?

Answer 1

在您的情况下，只需要具有不同参数的debounce操作符:

public final <U> Observable<T> debounce(Func1<? super T, ? extends Observable<U>> debounceSelector)

使用它可以筛选哪些事件可以延迟或不延迟:

RxSearchView.queryTextChanges(searchView)  
    .debounce(new Func1<CharSequence, Observable<CharSequence>>() {
        @Override
        public Observable<CharSequence> call(CharSequence charSequence) {
            if (charSequence.length() == 0) {
                return Observable.empty();
            } else {
                return Observable.<CharSequence>empty().delay(1, TimeUnit.SECONDS);
            }
        }
    })
    .subscribe(new Action1<CharSequence>() {
        @Override
        public void call(CharSequence charSequence) {
            Log.d(MainActivity.class.getSimpleName(), new Date().toGMTString() + " " + charSequence.length() + " :" + charSequence);
        }
    });

Answer 2

最简单的形式是将未绑定的可观察对象与手动触发器合并，如下所示:

RxSearchView.queryTextChanges(searchView)
        .debounce(1, TimeUnit.SECONDS)
        .mergeWith(Observable.just("")) // manually tigger onNext with empty search
        .subscribe(new Action1<CharSequence>() {
            @Override
            public void call(CharSequence charSequence) {
                presenter.loadUsers(charSequence.toString());
            }
        });