如何停止刷新recyclerview数据每次都滚动到最上面的位置

Question

我正在尝试用recyclerview做一个布局，比如视频。我做了一个recyclerview，它会在一定时间间隔后更新列表，但问题是在数据更新后，它会自动滚动到顶部位置。我想做一些像视频的东西。https://youtu.be/omcS-6LeKoo当将适配器数据RecyclerView notifyDataSetChanged scrolls更改为top position时，我尝试使用从SO RecyclerView scrolls到top position的链接，但无法解决此问题。下面是我的尝试

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = findViewById(R.id.recyclerViewId);

        handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
//                Toast.makeText(getApplicationContext(),"Updating",Toast.LENGTH_LONG).show();
                listShow();
                handler.postDelayed(this,1000);

            }
        },1000);

    }

void listShow(){

        retrofitApiCall = RetrofitInstance.getRetrofitInstance().create(RetrofitApiCall.class);
        Call<ModelClass_JSONParse> getDetails = retrofitApiCall;
        anime = ExtendedAnime.getAll();

        getDetails.enqueue(new Callback<ModelClass_JSONParse>() {
            @Override
            public void onResponse(Call<ModelClass_JSONParse> call, 
         Response<ModelClass_JSONParse> response) {
                Log.v("Res",response.toString());
                getWithValues = new HashMap<>();

                if (response.isSuccessful()){

                        list.add(mModelClass_adapter);
                    }
                    adapter = new Adapter(getApplicationContext(),list);
                    StaggeredGridLayoutManager layoutManager = new 
                    StaggeredGridLayoutManager(1,StaggeredGridLayoutManager.VERTICAL);
                    recyclerView.setLayoutManager(layoutManager);
                    recyclerView.setAdapter(adapter);
                    adapter.notifyDataSetChanged();

                }
            }

            @Override
            public void onFailure(Call<ModelClass_JSONParse> call, Throwable t) {
                Log.v("Res",call.toString());
            }
        });
    }

Answer 1

当响应发生更改时，您会一次又一次地设置适配器，所以您应该更改列表并在onCreate中设置适配器。

Arraylist<ModelClass_adapter> list =  new Arraylist<ModelClass_adapter>;
Adapter adapter;
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        recyclerView = findViewById(R.id.recyclerViewId);

        //set adapter here
        adapter = new Adapter(getApplicationContext(),list);
                    StaggeredGridLayoutManager layoutManager = new 
                    StaggeredGridLayoutManager(1,StaggeredGridLayoutManager.VERTICAL);
                    recyclerView.setLayoutManager(layoutManager);
                    recyclerView.setAdapter(adapter);

        handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
//                Toast.makeText(getApplicationContext(),"Updating",Toast.LENGTH_LONG).show();
                listShow();
                handler.postDelayed(this,1000);

            }
        },1000);

    }

void listShow(){

        retrofitApiCall = RetrofitInstance.getRetrofitInstance().create(RetrofitApiCall.class);
        Call<ModelClass_JSONParse> getDetails = retrofitApiCall;
        anime = ExtendedAnime.getAll();

        getDetails.enqueue(new Callback<ModelClass_JSONParse>() {
            @Override
            public void onResponse(Call<ModelClass_JSONParse> call, 
         Response<ModelClass_JSONParse> response) {
                Log.v("Res",response.toString());
                getWithValues = new HashMap<>();

                if (response.isSuccessful()){
                        list.clear();
                        list.add(mModelClass_adapter);
                    }

                    adapter.notifyDataSetChanged();

                }
            }

            @Override
            public void onFailure(Call<CurrencyModelClass_JSONParse> call, Throwable t) {
                Log.v("Res",call.toString());
            }
        });
    }

Answer 2

不要使用adapter.notifyDataSetChanged（）；方法，因为我认为您的主视图必须是包装内容，所以要么设置一个固定的高度，如150dp。

尝试不同的方法，如notifyItemChanged（）、notifyItemRangeChanged（）、notifyItemInserted（）等

Answer 3

这个问题可能是因为您在网络回调方法onSolutions（）中设置了新的适配器引用。尝试在on创建中设置适配器，然后在回调中更新数据集。

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    recyclerView = findViewById(R.id.recyclerViewId);
    recyclerView.setAdapter(yourAdapter);
}

在网络回调中，

@Override
        public void onResponse(Call<ModelClass_JSONParse> call, 
     Response<ModelClass_JSONParse> response) {
            Log.v("Res",response.toString());
            getWithValues = new HashMap<>();

            if (response.isSuccessful()){

                adapter.setDataSet(newDataList) //not change adapter reference,only update data set  

            }
        }

在适配器中实现setDataSet（）方法以更新列表，如下所示。

class YourAdapter extends RecyclerView.Adapter<>{
      priavate List<> list = new ArrayList();

      public void setDataSet(newList:List<>){ 
          list.clear();
          list.addAll(newList);
          notifyDataSetChanged();
      }
}