Rxjava入门(二)

来源：互联网发布：php argv 编辑：程序博客网时间：2024/06/17 19:44

基本使用方法

        //被观察者        Observable<Integer> observable = Observable.create(new ObservableOnSubscribe<Integer>() {            @Override            public void subscribe(ObservableEmitter<Integer> emitter) throws Exception {                emitter.onNext(1);                emitter.onNext(2);                emitter.onNext(3);                emitter.onComplete();            }        });        //观察者        Observer<Integer> observer = new Observer<Integer>() {            @Override            public void onSubscribe(Disposable d) {            }            @Override            public void onNext(Integer value) {                Log.d("meee",getClass()+":\n"+"value:"+value);            }            @Override            public void onError(Throwable e) {            }            @Override            public void onComplete() {            }        };        //被观察者 (被)订阅 观察者        observable.subscribe(observer);

链式调用

        Observable.create(new ObservableOnSubscribe<Integer>() {            @Override            public void subscribe(ObservableEmitter<Integer> emitter) throws Exception {                emitter.onNext(1);                emitter.onNext(2);                emitter.onNext(3);                emitter.onComplete();            }        }).subscribe(new Observer<Integer>() {                    @Override                    public void onSubscribe(Disposable d) {                    }                    @Override                    public void onNext(Integer value) {                        Log.d("meee", getClass() + ":\n" + "value:" + value);                    }                    @Override                    public void onError(Throwable e) {                    }                    @Override                    public void onComplete() {                    }                });

补充信息

建立关联之后, 被观察者才会开始发送事件. 也就是调用了subscribe() 方法之后才开始发送事件.

不带任何参数的subscribe() 表示下游不关心任何事件,你上游尽管发你的数据去吧, 老子可不管你发什么.

Emitter

Emitter,用于发送事件,共有三个方法onNext(T value)、onComplete()和onError(Throwable error);发送事件需要满足一定的规则:1.可以发送和接收无限个onNext2.onComplete,onError之后的事件可以继续发送,但不再被接收3.onComplete,onError可以不被发送4.onComplete,onError是唯一而且互斥的.5.发送多个onError报错,发送多个onComplete只有第一个生效

Disposable

Disposable,可以理解为一个开关Disposable.dispose()会把观察者和被观察者的联系切断,被观察者可以继续发送事件,但观察者无法继续接收事件

        Observable.create(new ObservableOnSubscribe<Integer>() {            @Override            public void subscribe(ObservableEmitter<Integer> emitter) throws Exception {                emitter.onNext(1);                emitter.onNext(2);                emitter.onNext(3);                emitter.onNext(4);                emitter.onNext(5);                emitter.onComplete();            }        }).subscribe(new Observer<Integer>() {            Disposable mDisposable;            @Override            public void onSubscribe(Disposable d) {                mDisposable=d;            }            @Override            public void onNext(Integer value) {                if (value==3){                    mDisposable.dispose();                }                Log.d("meee", getClass() + ":\n" + "value:" + value);            }            @Override            public void onError(Throwable e) {            }            @Override            public void onComplete() {            }        });//---------------------------------------日志--------------------------------------11-09 15:04:27.323 8834-8834/? D/meee: class com.junx.rxjava.RxJavaActivity$3:                                       value:111-09 15:04:27.323 8834-8834/? D/meee: class com.junx.rxjava.RxJavaActivity$3:                                       value:211-09 15:04:27.323 8834-8834/? D/meee: class com.junx.rxjava.RxJavaActivity$3:                                       value:3

Consumer

观察者之一,只关心onNext()事件

        Observable.create(new ObservableOnSubscribe<Integer>() {            @Override            public void subscribe(ObservableEmitter<Integer> emitter) throws Exception {                emitter.onNext(1);                emitter.onNext(2);                emitter.onNext(3);                emitter.onNext(4);                emitter.onNext(5);                emitter.onComplete();            }        }).subscribe(new Consumer<Integer>() {            @Override            public void accept(Integer integer) throws Exception {                Log.d("meee",getClass()+":\n"+"integer:"+integer);            }        });

线程控制

        Observable.create(new ObservableOnSubscribe<String>() {            @Override            public void subscribe(ObservableEmitter<String> e) throws Exception {                e.onNext("你好");                Log.d("meee",getClass()+"subscribe:\n"+Thread.currentThread().getName());            }        })       //创建一个线程发布事件                .subscribeOn(Schedulers.newThread())                //在主线程中接收(观察)事件                .observeOn(AndroidSchedulers.mainThread())                .subscribe(new Consumer<String>() {                    @Override                    public void accept(String s) throws Exception {                        Log.d("meee",getClass()+"accept:\n"+Thread.currentThread().getName());                    }                });//--------------------------------------日志-------------------------------------11-09 15:15:26.380 22897-22921/? D/meee: class com.junx.rxjava.RxJavaActivity$2subscribe:                                         RxNewThreadScheduler-111-09 15:15:26.394 22897-22897/? D/meee: class com.junx.rxjava.RxJavaActivity$1accept:                                         main

接收事件的线程可以切换多次

//多次切换线程        Observable.create(new ObservableOnSubscribe<String>() {            @Override            public void subscribe(ObservableEmitter<String> e) throws Exception {                e.onNext("你好");                Log.d("meee", getClass() + "subscribe:\n" + Thread.currentThread().getName());            }        })                .subscribeOn(Schedulers.newThread())                .observeOn(AndroidSchedulers.mainThread())                .doOnNext(new Consumer<String>() {                    @Override                    public void accept(String s) throws Exception {                        Log.d("meee",getClass()+":\n"+s+":"+Thread.currentThread().getName());                    }                })                .observeOn(Schedulers.io())                .subscribe(new Consumer<String>() {                    @Override                    public void accept(String s) throws Exception {                        Log.d("meee",getClass()+":\n"+s+":"+Thread.currentThread().getName());                    }                });//------------------------------------------------------------------------11-09 15:21:14.082 30304-30334/com.junx.rxjava D/meee: class com.junx.rxjava.RxJavaActivity$3subscribe:                                                       RxNewThreadScheduler-111-09 15:21:14.100 30304-30304/com.junx.rxjava D/meee: class com.junx.rxjava.RxJavaActivity$2:                                                       你好:main11-09 15:21:14.101 30304-30336/com.junx.rxjava D/meee: class com.junx.rxjava.RxJavaActivity$1:                                                       你好:RxCachedThreadScheduler-1

线程介绍

Schedulers.io() 代表io操作的线程, 通常用于网络,读写文件等io密集型的操作Schedulers.computation() 代表CPU计算密集型的操作, 例如需要大量计算的操作Schedulers.newThread() 代表一个常规的新线程AndroidSchedulers.mainThread() 代表Android的主线程

Rxjava与Retrofit的联合使用

阅读全文

0 0