compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
compile 'io.reactivex.rxjava2:rxjava:2.0.1'

compile 'com.jakewharton.rxbinding2:rxbinding:2.0.0'
compile 'com.jakewharton.rxbinding2:rxbinding-support-v4:2.0.0'
compile 'com.jakewharton.rxbinding2:rxbinding-appcompat-v7:2.0.0'

Observable<Long> mObservableCountTime = RxView.clicks(mBtnSendMsm)
  //防止重复点击
  .throttleFirst(MAX_COUNT_TIME, TimeUnit.SECONDS)
  //将点击事件转换成倒计时事件
  .flatMap(new Function<Object, ObservableSource<Long>>() {
    @Override
    public ObservableSource<Long> apply(Object o) throws Exception {
      //更新发送按钮的状态并初始化显现倒计时文字
      RxView.enabled(mBtnSendMsm).accept(false);
      RxTextView.text(mBtnSendMsm).accept("剩余 " + MAX_COUNT_TIME + " 秒");

      //在实际操作中可以在此发送获取网络的请求

      //返回 N 秒内的倒计时观察者对象。
      return Observable.interval(1, TimeUnit.SECONDS, Schedulers.io()).take(MAX_COUNT_TIME);
    }
  })
  //将递增数字替换成递减的倒计时数字
  .map(new Function<Long, Long>() {
    @Override
    public Long apply(Long aLong) throws Exception {
      return MAX_COUNT_TIME - (aLong + 1);
    }
  })
  .observeOn(AndroidSchedulers.mainThread());//切换到 Android 的主线程。

Consumer<Long> mConsumerCountTime = new Consumer<Long>() {
  @Override
  public void accept(Long aLong) throws Exception {
    //显示剩余时长。当倒计时为 0 时，还原 btn 按钮.
    if (aLong == 0) {
      RxView.enabled(mBtnSendMsm).accept(true);
      RxTextView.text(mBtnSendMsm).accept("发送验证码");
    } else {
      RxTextView.text(mBtnSendMsm).accept("剩余 " + aLong + " 秒");
    }
  }
};

 //订阅点击事件
 Disposable mDisposable = mObservableCountTime.subscribe(mConsumerCountTime);

//重置验证码按钮。
RxView.clicks(mBtnClean).subscribe(new Consumer<Object>() {
  @Override
  public void accept(Object o) throws Exception {
    if (mDisposable != null && !mDisposable.isDisposed()) {
      //停止倒计时
      mDisposable.dispose();
      //重新订阅
      mDisposable = mObservableCountTime.subscribe(mConsumerCountTime);
      //按钮可点击
      RxView.enabled(mBtnSendMsm).accept(true);
      RxTextView.text(mBtnSendMsm).accept("发送验证码");
    }
  }
});

@Override
protected void onDestroy() {
  super.onDestroy();
  if (mDisposable != null) {
    mDisposable.dispose();
  }
}