Question

基本上，我将RecyclerView与gridAdapter一起使用来从服务器加载图像。但是问题是RecyclerView的项目以一种古怪的方式闪烁。我已经尝试了所有可能的解决方案，但到目前为止，它们都没有起作用。

我试图将glide的版本从4.4.0更新为4.8.0，但这是徒劳的。我还尝试禁用RecyclerView的动画，但这无济于事。谁能帮我解决这个问题？

代码：

GridLayoutManager gridLayoutManager = new GridLayoutManager(v.getContext(),3);
gridLayoutManager.setSmoothScrollbarEnabled(true);
gridLayoutManager.setItemPrefetchEnabled(true);
gridLayoutManager.setInitialPrefetchItemCount(20);

posts_rView.setLayoutManager(gridLayoutManager);
posts_rView.setItemAnimator(null);
posts_rView.setHasFixedSize(true);

gridPostAdapter=new StarredAdapter(timelineDataList);
posts_rView.setAdapter(gridPostAdapter);

数据更新代码：

private  Emitter.Listener handlePosts = new Emitter.Listener(){

    @Override
    public void call(final Object... args){
        try {
            JSONArray jsonArray=(JSONArray)args[0];
            Needle.onMainThread().execute(() -> {
                timelineDataList.clear();
                swipeRefreshLayout.setRefreshing(false);

                for(int i=0;i<jsonArray.length();i++){
                    try {
                        //JSONArray arr=jsonArray.getJSONArray(i);
                        JSONObject ob=jsonArray.getJSONObject(i);

                        post_username=ob.getString("_pid");
                        post_fullname=ob.getString("owner_fullname");

                        if(ob.has("owner_profPic"))post_profPic=ob.getString("owner_profPic");
                        else post_profPic="";

                        post_time=ob.getString("time");

                        post_link=ob.getString("img_link");
                        likes_counter=ob.getString("likes_counter");
                        comments_counter=ob.getString("comments_counter");
                        if(ob.has("caption")) post_caption=ob.getString("caption");
                        else post_caption=null;

                        //Skipping Private Posts
                        if(ob.getString("private_post_stat").equals("yes")&&!post_username.equals(my_username)) {
                            continue;
                        }
                        else
                            private_post_stat = ob.getString("private_post_stat");

                        comment_disabled=ob.getString("comment_disabled");

                        share_disabled=ob.getString("share_disabled");

                        download_disabled=ob.getString("download_disabled");

                        if(ob.has("short_book_content")) short_book_content=ob.getString("short_book_content");
                        else short_book_content=null;
                        society_name_adp=ob.getString("society");

                        addTimelineData(post_username,post_fullname,post_profPic,post_time,post_link,post_caption,
                                private_post_stat,comment_disabled,share_disabled,download_disabled,likes_counter,comments_counter,short_book_content,society_name_adp);

                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }

                RecyclerView.Adapter adapter=posts_rView.getAdapter();
                posts_rView.setAdapter(null);
                posts_rView.setAdapter(adapter);
            });
        } catch (Exception e) {
            Log.e("error",e.toString());
        }
    }
};

private void addTimelineData(String username,String fullname,String post_profPic,String time,String img_link,String caption,
                             String private_post_stat,String comment_disabled,String share_disabled,String download_disabled,String likes_counter,
                             String comments_counter,String short_book_content,String society_name_adp){
    boolean isRepeated = false;
    for(TimelineData data:timelineDataList){
        if (data.getTime().equals(time)) {
            isRepeated = true;
        }
    }

    if(!isRepeated){
        timelineDataList.add(new TimelineData(username,fullname,post_profPic,time,img_link,caption,private_post_stat,comment_disabled,share_disabled,download_disabled,likes_counter,comments_counter,short_book_content,society_name_adp));
        gridPostAdapter.notifyDataSetChanged();
        // posts_rView.scrollToPosition(gridPostAdapter.getItemCount()-1);
       // posts_rView.scrollToPosition(0);
    }

     //gridPostAdapter.notifyItemInserted(timelineDataList.size()-1);
}

适配器类：

@Override
public void onBindViewHolder(StarViewHolder holder, int position) {

    //loading img
    Glide.with( parent.getContext()).asBitmap().load(arrayList.get(position)).apply(new RequestOptions()
        .override(200, 200)
        .dontAnimate()
        .placeholder(new ColorDrawable(Color.parseColor("#20001919"))))
        .thumbnail(0.1f)
        .into(holder.img);
}

@Override
public int getItemCount() {
    return arrayList.size();
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public int getItemViewType(int position) {
    return position;
}

Answer 1

我还不太了解为什么在您的情况下会发生闪烁和重新定位到第一个元素的情况，因为我看不到您的RecyclerView的更新政策。但是，我想提出一些可能解决问题的方法。

我建议您在设置setInitialPrefetchItemCount时删除setItemPrefetchEnabled和GridLayoutManager配置。如果您的嵌套RecyclerView不是您的情况，这将有帮助。
每次从服务器更新数据时，都要设置适配器。我猜您在滚动项目时正在调用更新操作代码。你不应该。此外，每次更新数据集时，请不要设置RecyclerView的适配器。每次更新后，只需使用notifyDataSetChanged。不要清除timelineDataList并附加新项，然后在适配器上调用notifyDataSetChanged。
每次插入列表后，您正在notifyDataSetChanged中呼叫addTimelineData。仅应在将所有元素添加到列表中后才能执行此操作。

因此，我想提出以下代码来设置您的适配器并更新您的RecyclerView。请注意，我尚未测试代码，您可能必须修改一些可能发生的错误。

用于设置布局管理器和适配器的代码。

GridLayoutManager gridLayoutManager = new GridLayoutManager(v.getContext(),3);
posts_rView.setLayoutManager(gridLayoutManager);
posts_rView.setHasFixedSize(true);

gridPostAdapter = new StarredAdapter(timelineDataList);
posts_rView.setAdapter(gridPostAdapter);

用于更新列表的代码。

private  Emitter.Listener handlePosts = new Emitter.Listener(){

    @Override
    public void call(final Object... args){
        try {
            JSONArray jsonArray = (JSONArray)args[0];
            Needle.onMainThread().execute(() -> {

                // Do not clear the list. Just append the new data in the list instead
                // timelineDataList.clear();

                swipeRefreshLayout.setRefreshing(false);

                for(int i = 0; i < jsonArray.length(); i++){
                    try {
                        JSONObject ob = jsonArray.getJSONObject(i);

                        post_username = ob.getString("_pid");
                        post_fullname = ob.getString("owner_fullname");
                        if(ob.has("owner_profPic")) post_profPic = ob.getString("owner_profPic");
                        else post_profPic = "";

                        post_time = ob.getString("time");

                        post_link = ob.getString("img_link");
                        likes_counter = ob.getString("likes_counter");
                        comments_counter = ob.getString("comments_counter");
                        if(ob.has("caption")) post_caption = ob.getString("caption");
                        else post_caption = null;

                        //Skipping Private Posts
                        if(ob.getString("private_post_stat").equals("yes")&&!post_username.equals(my_username)) {
                            continue;
                        }
                        else
                            private_post_stat = ob.getString("private_post_stat");

                        comment_disabled = ob.getString("comment_disabled");
                        share_disabled = ob.getString("share_disabled");
                        download_disabled = ob.getString("download_disabled");

                        if (ob.has("short_book_content")) short_book_content = ob.getString("short_book_content");
                        else short_book_content = null;

                        society_name_adp = ob.getString("society");
                        addTimelineData(post_username, post_fullname, post_profPic, post_time, post_link,post_caption, private_post_stat, comment_disabled, share_disabled, download_disabled, likes_counter, comments_counter, short_book_content, society_name_adp);
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }

                gridPostAdapter.notifyDataSetChanged();
            });

        } catch (Exception e) {
            Log.e("error",e.toString());
        }
    }
};

private void addTimelineData(String username, String fullname, String post_profPic, String time, String img_link, String caption, String private_post_stat, String comment_disabled, String share_disabled, String download_disabled, String likes_counter, String comments_counter, String short_book_content, String society_name_adp) {

    boolean isRepeated = false;
    for(TimelineData data:timelineDataList){
        if (data.getTime().equals(time)) {
            isRepeated = true;
        }
    }

    if(!isRepeated){
        timelineDataList.add(new TimelineData(username,fullname,post_profPic,time,img_link,caption,private_post_stat,comment_disabled,share_disabled,download_disabled,likes_counter,comments_counter,short_book_content,society_name_adp));

        // Do not call notifyDataSetChanged each time you are adding an item. This will be called in the call function above. So remove this line.
        // gridPostAdapter.notifyDataSetChanged();
    }
}

请尝试在服务器端API中添加分页（如果尚未提供），以便您可以获取下20个数据集，而无需在向下滚动时再次获取全部数据。

希望有帮助。

RecyclerView会自动向上滚动并闪烁

1 个答案: