RxJava学习（5.9）

1.RxJava 操作符

just、from、defer、interval（间隔）、range（范围）、repeat(重复)、timer

变换操作符

map、flatMap、concatMap、filter（过滤）、skip（跳过前面的元素）、take(指定元素)

2、使用场景

界面防抖动（throttleFirst）

RxView.clicks(mBtnTest2).throttleFirst(1L, TimeUnit.SECONDS).subscribe(new Action1<Void>() {
        @Override
        public void call(Void aVoid) {
            Toast.makeText(MainActivity.this, "button2 clicked", Toast.LENGTH_SHORT).show()
        }

定时任务（timer）

private void startTimerTask() {
        Observable.timer(2, TimeUnit.SECONDS).subscribe(new Action1<Long>() {
            @Override
            public void call(Long aLong) {
                Log.d("MainActivity", "start execute task:" + Thread.currentThread().getName());
            }
        });

周期任务（interval）

private void startIntervalTask() {
        Observable.interval(5, TimeUnit.SECONDS).subscribe(new Action1<Long>() {
            @Override
            public void call(Long aLong) {
                Log.d("MainActivity", "start task:" + Thread.currentThread().getName());
            }
        });

响应式界面(注册、登录 combineLatest）

EditText mEditUsername = (EditText) findViewById(R.id.editText3)
        EditText mEditPwd = (EditText) findViewById(R.id.editText4)
        final Button mBtnLogin = (Button) findViewById(R.id.button2)
        mBtnLogin.setEnabled(false)

        Observable<CharSequence> usernameOb = RxTextView.textChanges(mEditUsername)
        Observable<CharSequence> pwdOb = RxTextView.textChanges(mEditPwd)

        Observable.combineLatest(usernameOb, pwdOb, new Func2<CharSequence, CharSequence,="" Boolean="">() {
            @Override
            public Boolean call(CharSequence username, CharSequence pwd) {

                return !TextUtils.isEmpty(username) && !TextUtils.isEmpty(pwd)
            }
        }).subscribe(new Action1<Boolean>() {
            @Override
            public void call(Boolean isLogin) {
                mBtnLogin.setEnabled(isLogin)
            }

线程调度

Observable.just("https://ss2.baidu.com/-vo3dSag_xI4khGko9WTAnF6hhy/image/h%3D200/sign=4db5130a073b5bb5a1d727fe06d2d523/cf1b9d16fdfaaf51965f931e885494eef11f7ad6.jpg")
          .map(new Func1<String, Drawable>() {
              @Override
              public Drawable call(String s) {
                  try {
                      Drawable src = Drawable.createFromStream(new URL(s).openStream(), "src");
                      return src;
                  }catch (IOException e){

                  }
                  return null;
              }
          }).subscribeOn(Schedulers.io())                 //发射者 在io 子线程操作
            .observeOn(AndroidSchedulers.mainThread())    //接收者  在主线程操作
            .subscribe(new Action1<Drawable>() {
                @Override
                public void call(Drawable drawable) {
                    if (drawable != null) {
                        mIvLogo.setImageDrawable(drawable);
                    }
                }
            });