Rxjava 转换操作符

最新推荐文章于 2023-03-11 19:41:42 发布

阿福-jacob

最新推荐文章于 2023-03-11 19:41:42 发布

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本文链接：https://blog.youkuaiyun.com/qq_33994844/article/details/62422644

buffer:在时间间隔内缓存结果，类似于buffer缓存一个list集合，区别在于window将这个结果集合封装成了list,详解

window:在时间间隔内缓存结果，类似于buffer缓存一个list集合，区别在于window将这个结果集合封装成了observable,详解

scan:遍历源Observable产生的结果,再按照自定义规则进行运算,依次输出每次计算后的结果给订阅者,call回调第一个参数是上次的结算结果,第二个参数是当此源observable的输入值,注意:当执行源observable输入的第一个时,并不会回调call函数,也就是说第一次并不参与运算,直接输给订阅者

Observable.range(1, 10).scan(new Func2<Integer, Integer, Integer>() {
    @Override
    public Integer call(Integer sum, Integer integer) {
        Log.e(TAG,"------->sum:" + sum + "   integer:" + integer);
        return sum + integer;
    }
}).subscribe(new Observer<Integer>() {
    @Override
    public void onCompleted() {
        Log.e(TAG,"------>onCompleted()");
    }

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

    @Override
    public void onNext(Integer integer) {
        Log.e(TAG,"------>onNext()" + integer);
    }
});

03-16 15:00:00.202 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()1
03-16 15:00:00.202 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:1   integer:2
03-16 15:00:00.203 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()3
03-16 15:00:00.203 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:3   integer:3
03-16 15:00:00.203 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()6
03-16 15:00:00.203 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:6   integer:4
03-16 15:00:00.203 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()10
03-16 15:00:00.203 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:10   integer:5

03-16 15:00:00.203 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()15
03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:15   integer:6
03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()21
03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:21   integer:7
03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()28
03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:28   integer:8
03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()36

03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:36   integer:9
03-16 15:00:00.204 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()45
03-16 15:00:00.205 23775-23775/com.iwith.smart E/RxjavaActivity: ------->sum:45   integer:10
03-16 15:00:00.205 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onNext()55
03-16 15:00:00.205 23775-23775/com.iwith.smart E/RxjavaActivity: ------>onCompleted()

cast:在发射之前强制将Observable发射的所有数据转换为指定类型

public void cast() {
    List<Person> list = new ArrayList<>();
    for (int i = 0; i < 30; i++) {
        list.add(new Male(true, "i" + i));
    }
    Observable.from(list).cast(Male.class).subscribe(new Subscriber<Male>() {
        @Override
        public void onCompleted() {

        }

        @Override
        public void onError(Throwable e) {

        }

        @Override
        public void onNext(Male s) {
            Log.i(tag, "name:" + s.name + "\n hasJJ:" + s.hasJJ);
        }
    });
}

class Person {
    String name;

    public Person(String name) {
        this.name = name;
    }
}

class Male extends Person {
    public boolean hasJJ;

    public Male(boolean hasJJ, String name) {
        super(name);
        this.hasJJ = hasJJ;
    }
}
//多态，我们用Person接收Male对象，然后通过cast转成Male类型。有点instanceof的意思。

Map:将一个数据类型转成另一种数据类型

Observable.just(1,55,99,33)
        .map(new Func1<Integer, Student>() {
            @Override
            public Student call(Integer integer) {
                return new Student(integer,null);
            }
        })
        .subscribe(new Action1<Student>() {
            @Override
            public void call(Student student) {
                Log.e(TAG,student.toString());
            }
        });

03-16 15:22:28.421 23775-23775/com.iwith.smart E/RxjavaActivity: Student{name=1, mList=null}
03-16 15:22:28.421 23775-23775/com.iwith.smart E/RxjavaActivity: Student{name=55, mList=null}
03-16 15:22:28.421 23775-23775/com.iwith.smart E/RxjavaActivity: Student{name=99, mList=null}
03-16 15:22:28.421 23775-23775/com.iwith.smart E/RxjavaActivity: Student{name=33, mList=null}

concatMap:是将源Observable转换成对各操作符，然后又链接返回给源Observable，这与flatMap十分相似，最大的区别:concatMap 是保证结果的顺序性，就是顺序与输入一致.详解

switchMap()和flatMap()很像，除了一点:当源Observable发射一个新的数据项时，如果旧数据项订阅还未完成，就取消旧订阅数据和停止监视那个数据项产生的Observable,开始监视新的数据项.详解

compose:详解