RX(一)

建议，先去了解观察者模式。

前期工作：引入RX的包

build.gradle脚本里面的

dependencies｛

compile 'io.reactivex:rxjava:1.1.0'
compile 'io.reactivex:rxandroid:1.1.0'

｝

需要用到的类  Observable  Subscriber

第一种写法：
1.创建被观察者

Observable<String> observable = Observable.create(new Observable.OnSubscribe<String>() {
    @Override
    public void call(Subscriber<? super String> subscriber) {
        if (!subscriber.isUnsubscribed()) {
            subscriber.onNext("hello");
            subscriber.onNext("hi");
            subscriber.onNext("world");
            subscriber.onNext("ok");
            subscriber.onCompleted(); // 结尾
        }
    }
});

2. 定义观察者

Subscriber<String> subscriber = new Subscriber<String>() {
    @Override
    public void onCompleted() {
        Log.e(TAG, "onCompleted");
    }

    @Override
    public void onError(Throwable e) {
        Log.e(TAG, "onError");
    }

    @Override
    public void onNext(String str) {
        Log.e(TAG, str);
    }
};
3.关联被观察者
observable.subscribe(subscriber);   

第二种写法：

Observable.create(new Observable.OnSubscribe<Integer>() {
        @Override
        public void call(Subscriber<? super Integer> subscriber) {

            if (!subscriber.isUnsubscribed()) {
                for (int i = 0; i < 10; i++) {
                    subscriber.onNext(i);
                }
                subscriber.onCompleted();
            }
        }
    }).subscribe(new Subscriber<Integer>() {
        @Override
        public void onCompleted() {
            Log.e(TAG, "onCompleted");
        }

        @Override
        public void onError(Throwable e) {
            Log.e(TAG, "onError");
        }

        @Override
        public void onNext(Integer integer) {
            Log.e(TAG, String.valueOf(integer));
        }
    });
}