小试牛刀RxJava2之首页检查

Posted ihrthk

tags:

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前言

当我第一次听说RxJava是在2015年的11月,掐指一算距今过去了1年多了,现在RxJava2都发布了。现在公司项目的的业务需要,有一块逻辑涉及到子线程和主线程的来回切换。如果使用传统的Thread+Handler的写法,写出来的代码就跳来跳去,还有可能出现多次嵌套。很利于阅读理解里面的逻辑和后期的维护开发。早就听说RxJava的大名,通过响应式编程很好的处理异步问题。这次正好有这个机会,自己就动手实践一下。

产品流程

只有前一个执行完成(不管是否成功),才能执行后面一个。
1. 新手引导
2. 检查升级
3. 弹窗视图

一张图你就懂了

开发流程

  1. 检查sp里的isFirst-子线程
  2. 显示带动画的引导界面-主线程
  3. 监听动画结束-主线程
  4. 监听引导界面的点击事件-主线程
  5. 隐藏带动画的引导界-主线程
  6. 监听动画结束-主线程
  7. 将sp里的isFirst置为false-子线程
  8. 发起检查版本请求-子线程
  9. 显示版本更新的dialog-主线程
  10. 监听对话框消失-主线程
  11. 发起获取弹窗数据的请求-子线程
  12. 显示弹窗视图-主线程
Disposable disposable = Observable
                .create(new ObservableOnSubscribe<Boolean>() 
                    @Override
                    public void subscribe(ObservableEmitter<Boolean> e) throws Exception 
                        e.onNext(PreferenceManager
                                .getDefaultSharedPreferences(MainActivity.this)
                                .getBoolean("isFirst", true));
                    
                )
                .subscribeOn(Schedulers.io())
                .observeOn(androidSchedulers.mainThread())
                .flatMap(new Function<Boolean, ObservableSource<Boolean>>() 
                    @Override
                    public ObservableSource<Boolean> apply(Boolean aBoolean) throws Exception 
                        if (aBoolean) 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(final ObservableEmitter<Boolean> e) throws Exception 
                                    AlphaAnimation alphaAnimation = new AlphaAnimation(0.1f, 1.0f);
                                    alphaAnimation.setDuration(2000);
                                    alphaAnimation.setAnimationListener(new Animation.AnimationListener() 
                                        @Override
                                        public void onAnimationStart(Animation animation) 

                                        

                                        @Override
                                        public void onAnimationEnd(Animation animation) 
                                            if (!e.isDisposed()) 
                                                e.onNext(true);
                                            
                                        

                                        @Override
                                        public void onAnimationRepeat(Animation animation) 

                                        
                                    );
                                    fragment_home_guide.setVisibility(View.VISIBLE);
                                    fragment_home_guide.startAnimation(alphaAnimation);
                                
                            );
                         else 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(ObservableEmitter<Boolean> e) throws Exception 
                                    e.onNext(false);
                                
                            );
                        
                    
                )
                .flatMap(new Function<Boolean, ObservableSource<Boolean>>() 
                    @Override
                    public ObservableSource<Boolean> apply(Boolean aBoolean) throws Exception 
                        if (aBoolean) 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(final ObservableEmitter<Boolean> e) throws Exception 
                                    fragment_home_guide.setOnClickListener(new View.OnClickListener() 
                                        @Override
                                        public void onClick(View view) 
                                            if (!e.isDisposed()) 
                                                e.onNext(true);
                                            
                                        
                                    );
                                    e.setDisposable(new Disposable() 
                                        @Override
                                        public void dispose() 
                                            fragment_home_guide.setOnClickListener(null);
                                        

                                        @Override
                                        public boolean isDisposed() 
                                            return true;
                                        
                                    );
//                                e.add(new MainThreadSubscription() 
//                                    @Override
//                                    protected void onUnsubscribe() 
//                                        fragment_home_guide.setOnClickListener(null);
//                                    
//                                );
                                
                            );
                         else 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(ObservableEmitter<Boolean> e) throws Exception 
                                    e.onNext(false);
                                
                            );
                        
                    
                )
                .flatMap(new Function<Boolean, ObservableSource<Boolean>>() 
                    @Override
                    public ObservableSource<Boolean> apply(Boolean aBoolean) throws Exception 
                        if (aBoolean) 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(final ObservableEmitter<Boolean> e) throws Exception 
                                    AlphaAnimation alphaAnimation = new AlphaAnimation(1.0f, 0.1f);
                                    alphaAnimation.setDuration(2000);
                                    alphaAnimation.setAnimationListener(new Animation.AnimationListener() 
                                        @Override
                                        public void onAnimationStart(Animation animation) 

                                        

                                        @Override
                                        public void onAnimationEnd(Animation animation) 
                                            if (!e.isDisposed()) 
                                                e.onNext(true);
                                            
                                        

                                        @Override
                                        public void onAnimationRepeat(Animation animation) 

                                        
                                    );
                                    fragment_home_guide.setVisibility(View.GONE);
                                    fragment_home_guide.startAnimation(alphaAnimation);
                                
                            );
                         else 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(ObservableEmitter<Boolean> e) throws Exception 
                                    e.onNext(false);
                                
                            );
                        
                    
                )
                .observeOn(Schedulers.io())
                .map(new Function<Boolean, Boolean>() 
                    @Override
                    public Boolean apply(Boolean aBoolean) throws Exception 
                        if (aBoolean) 
                            PreferenceManager
                                    .getDefaultSharedPreferences(MainActivity.this)
                                    .edit()
                                    .putBoolean("isFirst", false)
                                    .apply();
                        
                        return aBoolean;
                    
                )
                .flatMap(new Function<Boolean, ObservableSource<Version>>() 
                    @Override
                    public ObservableSource<Version> apply(Boolean aBoolean) throws Exception 
                        Thread.sleep(300);

                        return new Observable<Version>() 
                            @Override
                            protected void subscribeActual(Observer<? super Version> observer) 
                                observer.onNext(new Version());
                            
                        ;
                    
                )
                .observeOn(AndroidSchedulers.mainThread())
                .flatMap(new Function<Version, ObservableSource<Boolean>>() 
                    @Override
                    public ObservableSource<Boolean> apply(Version version) throws Exception 
                        if (version == null) 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(ObservableEmitter<Boolean> e) throws Exception 
                                    e.onNext(false);
                                
                            );
                         else 
                            return Observable.create(new ObservableOnSubscribe<Boolean>() 
                                @Override
                                public void subscribe(final ObservableEmitter<Boolean> e) throws Exception 
                                    new AlertDialog.Builder(MainActivity.this)
                                            .setTitle("发现新版本")
                                            .setMessage("更新内容")
                                            .setPositiveButton("升级", new DialogInterface.OnClickListener() 
                                                @Override
                                                public void onClick(DialogInterface dialogInterface, int i) 

                                                
                                            )
                                            .setNegativeButton("取消", new DialogInterface.OnClickListener() 
                                                @Override
                                                public void onClick(DialogInterface dialogInterface, int i) 

                                                
                                            )
                                            .setOnDismissListener(new DialogInterface.OnDismissListener() 
                                                @Override
                                                public void onDismiss(DialogInterface dialogInterface) 
                                                    e.onNext(true);
                                                
                                            )
                                            .create().show();
                                
                            );
                        
                    
                )
                .observeOn(Schedulers.io())
                .flatMap(new Function<Boolean, ObservableSource<String>>() 

                    @Override
                    public ObservableSource<String> apply(Boolean aBoolean) throws Exception 
                        Thread.sleep(300);
                        return Observable.create(new ObservableOnSubscribe<String>() 
                            @Override
                            public void subscribe(ObservableEmitter<String> e) throws Exception 
                                e.onNext("ok");
                            
                        );
                    
                )
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Consumer<String>() 
                    @Override
                    public void accept(String s) throws Exception 
                        Toast.makeText(MainActivity.this, s, Toast.LENGTH_SHORT).show();
                    
                );

        disposables.add(disposable);

小结

在熟悉了RxJava的基本概念之后,写Rx代码确实比较顺手,有一种行云流水的感觉。值得注意的是,使用RxJava进行开发并不会减少原有代码量,反而有一定的增加。遇到的主要问题就是,要理解并区分subscribeOn和observeOn的线程控制,以及map和flatMap的变换。
我的粗浅理解是:subscribeOn控制的是最前面的create和最后的subscribe,而observeOn控制的是后面的变化操作。map是Observable对象没有改变,执行形式变了,比如有File变成Bitmap。而flatMap是Observable发生了改变,比如以前被观察的对象是sp里的isFirst,现在变成了引导界面的动画结束。
最后附上demo地址:https://github.com/ihrthk/RxHomeCheck

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