Question

我正在从适配器中的演示者请求图像：

 // Called when the url of a tab changes.
function checkForValidUrl(tabId, changeInfo, tab) {

  if (tab.url.indexOf('calendar') > -1) {

         chrome.tabs.insertCSS(null, {code: '.ui-sch input { direction: rtl }'});
         chrome.tabs.insertCSS(null, {code: '.ui-sch textarea { direction: rtl }'});
  }
};

// Listen for any changes to the URL of any tab.
chrome.tabs.onUpdated.addListener(checkForValidUrl);

我应该在重新使用@Override public void onBindViewHolder(SiteAdapter.ViewHolder holder, int position) { Site site = sites.get(position); holder.siteName.setText(site.getName()); requestHolderLogo(holder, site.getLinks().getLogoUrl()); } private void requestHolderLogo(final ViewHolder holder, final String logoUrl) { compositeSubscription.add( presenter.bitmap(logoUrl) .subscribe( bitmap -> { holder.siteLogo.setImageBitmap(bitmap); holder.siteLogo.setVisibility(View.VISIBLE); }, error -> { holder.siteName.setVisibility(View.VISIBLE); }) ); }时取消订阅。这很容易。

但是当视图被销毁时如何停止所有订阅？我也应该使演示者引用无效以避免内存泄漏

Answer 1

我认为最好的办法是：

在subscription

SiteAdapter.ViewHolder

unsubscribe subscription onBindViewHolder中的ViewHolder对象（重新使用CompositeSubscription时调用此对象）
将adapter对象保留在onDetachedFromRecyclerView
使用Adapter的{{1}}方法unsubscribe compositeSubscription

像这样：

public class SiteAdapter extends RecyclerView.Adapter<SiteAdapter.ViewHolder> {

    private CompositeSubscription compositeSubscription = new CompositeSubscription();

    // other needed SiteAdapter methods

    @Override
    public void onBindViewHolder(SiteAdapter.ViewHolder holder, int position) {
        if (holder.subscription != null && !holder.subscription.isUnsubscribed()) {
            compositeSubscription.remove(holder.subscription);
            // this will unsubscribe the subscription as well
        }
        Site site = sites.get(position);
        holder.siteName.setText(site.getName());
        requestHolderLogo(holder, site.getLinks().getLogoUrl());
    }

    private void requestHolderLogo(final SiteAdapter.ViewHolder holder, final String logoUrl) {
        holder.subscription = presenter.bitmap(logoUrl)
                .subscribe(
                        bitmap -> {
                            holder.siteLogo.setImageBitmap(bitmap);
                            holder.siteLogo.setVisibility(View.VISIBLE);
                        },
                        error -> {
                            holder.siteName.setVisibility(View.VISIBLE);
                        });
        compositeSubscription.add(holder.subscription);
    }

    @Override
    public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
        compositeSubscription.unsubscribe();
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {

        public Subscription subscription;

        // some holder-related stuff

        public ViewHolder(View itemView) {
            super(itemView);
            // init holder
        }
    }
}

Answer 2

可以调用public void onViewRecycled(@NonNull VH holder)

Answer 3

对于其他有相同问题的用户：仅当将适配器在onPause（活动，片段）或onDetachFromWindow（活动，片段）中设置为null时，才调用适配器中的viewDetachedFromWindow

recyclerview.setAdapter（null）

然后您获得viewDetachedFromWindow（...），可以在其中释放内部状态和订阅。我会在绑定上设置您的订阅，请确保在释放您的每个绑定调用之前释放旧订阅，因为视图可以回收。

另一种可能性是在工厂中增加自定义视图，而不是仅增加布局。然后，您可以在自定义视图onDetachFromWindow（）中进行清理。您也可以在不将适配器设置为null的情况下获得onDetachedFromWindow。

RecyclerView适配器的生命周期是什么？

3 个答案: