The Debounce operator filters out items emitted by the source Observable that are rapidly followed by another emitted item.
public final Observable<T> debounce(long timeout, TimeUnit unit); // 默认执行线程 Schedulers.computation() public final Observable<T> debounce(long timeout, TimeUnit unit, Scheduler scheduler);
快速点击按钮，执行某个操作。
比如美团APP中的选择套餐：由左图的0份快速点击到右图的7份，然后根据选中份数计算总价。
// NumberPickerView.java ... plusView.setOnClickListener(v - > { selectCount++; countTv.setText(selectCount + ""); onChangeListener.onChange(dealId, selectCount); // dealId为当前套餐的id }); public interface OnChangeListener { onChange(int dealId, int selectCount); }
// activity ... numberPickerView.setOnChangeListener((dealId, selcetCount) -> { calculateDealPrice(dealId, selectCount); }); private calculateDealPrice(int dealId, int selectCount) { ... // 计算价格 }
对于这种快速点击，我们其实需要的是对第7次进行计算，中间的一系列暂存态是没必要计算的，使用debounce来解决。
RxView.clicks(plusView) .map(aVoid -> { selectCount++; countTv.setText(selectCount + ""); return selectCount; } .debounce(400, TimeUnit.MILLISECONDS)) .observeOn(AndroidSchedulers.mainThread()) .subcribe(count -> onChangeListener.onChange(dealId, selectCount), Throwable::printStackTrace);
缺点:
1.NumberPickerView依赖了 com.jakewharton.rxbinding:rxbinding:x.x.x
2.NumberPickerView中plusView被强制增加了400ms的debounce操作
// NumberPickerView.java ... plusView.setOnClickListener(v - > { selectCount++; countTv.setText(selectCount + ""); onChangeListener.onChange(dealId, selectCount); // dealId为当前套餐的id });
// activity ... PublishSubject<SelectParams> subject = PublishSubject.create(); numberPickerView.setOnChangeListener((dealId, selectCount) -> { subject.onNext(new SelectParams(dealId, selectCount)); }); subject.debounce(400, TimeUnit.MILLISECONDS) .observeOn(AndroidSchedulers.mainThread()) .subscribe(selectParams -> calculateDealPrice(selectParams.dealId, selectParams.selectCount), Throwable::printStackTrace); class SelectParams { int dealId; int selectCount; SelectParams(int dealId, int selectCont) { this.dealId = dealId; this.selectCount = selectCount; } } private calculateDealPrice(int dealId, int selectCount) { ... // 计算价格 }
此时NumberPickerView不再依赖第三方库，适用性提高。
参考：http://reactivex.io/documentation/operators.html
原文：http://www.cnblogs.com/ruyingxiangsui/p/6082777.html