android - 可迭代的 .zip 问题 (rxJava)

Question

我有四个 Observable 的代码。我将 Observable.zip 应用到它们:

Observable<Currencies> usd = CoinMarket.getMarketApi().getCurrencies();
    Observable<Currencies> rub = CoinMarket.getMarketApi().getCurrencies("RUB");
    Observable<Currencies> eur = CoinMarket.getMarketApi().getCurrencies("EUR");
    Observable<Currencies> btc = CoinMarket.getMarketApi().getCurrencies("BTC");

    List<Observable<Currencies>> singles = new ArrayList<>();
    singles.add(usd);
    singles.add(rub);
    singles.add(eur);
    singles.add(btc);

    Observable<Currencies> c = Observable.zip(singles, new Function<Currencies[], Currencies>() {
                @Override
                public Currencies apply(@NotNull Currencies[] objects) throws Exception {
                    return ramming(objects);
                }
            });

但是我得到了错误:

消息说未找到具有此类签名的方法(也许我不对)，但我去声明并查看签名，有点像，是合适的。

 public static <T, R> Observable<R> zip
 (Iterable<? extends ObservableSource<? extends T>> sources,
 Function<? super Object[], ? extends R> zipper)

我做错了什么？

P.S:我注意到这个错误 RxJava2Iterableisbroken

Answer 1

这不是错误。你需要一个Function<? super Object[]由于 Java 的泛型限制。这也在 the Javadocs of zips 中进行了解释。 .

Observable<Currencies> usd = CoinMarket.getMarketApi().getCurrencies();
Observable<Currencies> rub = CoinMarket.getMarketApi().getCurrencies("RUB");
Observable<Currencies> eur = CoinMarket.getMarketApi().getCurrencies("EUR");
Observable<Currencies> btc = CoinMarket.getMarketApi().getCurrencies("BTC");

List<Observable<Currencies>> singles = new ArrayList<>();
singles.add(usd);
singles.add(rub);
singles.add(eur);
singles.add(btc);

Observable<Currencies> c = Observable.zip(singles, new Function<Object[], Currencies>() {
            @Override
            public Currencies apply(@NotNull Object[] objects) throws Exception {
                Currencies[] currencies = new Currencies[objects.length];
                for (int i = 0; i < objects.length; i++) {
                     currencies[i] = (Currencies)objects[i];
                }
                return ramming(currencies);
            }
        });