android - 在 recyclerview 中多次使用 "setAdapter()"是否有问题？

Question

实际上我正在从服务器获取数据并在我的 recyclerview 上显示。但它什么也没显示。即使在引用了很多问题之后，我的问题仍无法解决，但后来我尝试在获取数据后使用 setAdapter() 方法，现在我的问题已解决。但我要问的是 多次使用 setAdapter 是否异常？。在我的第一次尝试中，我先设置适配器，然后在从服务器获取数据后尝试使用 adp.notifyDataSetChanged()。但现在我在获取数据后再次设置适配器。

代码:

private List<TImelineDataList> timelineDatalist;
@Override
public void onViewCreated(@NonNull View v, @Nullable Bundle savedInstanceState) {


    timelineDataList= new ArrayList<>();
    adapter=new CustomRecyclerViewAdapter(timelineDataList);
    recyclerView.setItemViewCacheSize(30);
    recyclerView.setDrawingCacheEnabled(true);
    recyclerView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
    recyclerView.setLayoutManager(new 
    LinearLayoutManager(ctx,LinearLayoutManager.HORIZONTAL,false));
    recyclerView.setAdapter(adapter);

}
 void addTimelineData(String email,String time,String img_link,String caption){
    timelineDataList.add(new TimelineData(email,time,img_link,caption));
    adapter=new CustomRecyclerViewAdapter(timelineDataList);
    adapter.notifyDataSetChanged();
    recyclerView.setAdapter(adapter);
}
  private  Emitter.Listener handlePosts = new Emitter.Listener(){

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

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

                       demo_time=ob.getString("time");

                       demo_link=ob.getString("img_link");

                       demo_caption=ob.getString("caption");


                       addTimelineData(demo_email,demo_time,demo_link,demo_caption);

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




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

Answer 1

终于找到问题了。问题出在构造适配器两次。现在我已经删除了下一个适配器构造和 setAdapter()，并且它可以正常工作。

上一个代码:

private List<TImelineDataList> timelineDatalist;
@Override
public void onViewCreated(@NonNull View v, @Nullable Bundle savedInstanceState) {


    timelineDataList= new ArrayList<>();
    **adapter=new CustomRecyclerViewAdapter(timelineDataList);**//Here
    recyclerView.setItemViewCacheSize(30);
    recyclerView.setDrawingCacheEnabled(true);
    recyclerView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
    recyclerView.setLayoutManager(new 
    LinearLayoutManager(ctx,LinearLayoutManager.HORIZONTAL,false));
    recyclerView.setAdapter(adapter);

}
 void addTimelineData(String email,String time,String img_link,String caption){
    timelineDataList.add(new TimelineData(email,time,img_link,caption));
    **adapter=new CustomRecyclerViewAdapter(timelineDataList);**//Here
    adapter.notifyDataSetChanged();
    recyclerView.setAdapter(adapter);
}
  private  Emitter.Listener handlePosts = new Emitter.Listener(){

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

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

                       demo_time=ob.getString("time");

                       demo_link=ob.getString("img_link");

                       demo_caption=ob.getString("caption");


                       addTimelineData(demo_email,demo_time,demo_link,demo_caption);

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




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

新代码:

private List<TImelineDataList> timelineDatalist= new ArrayList<>();;
@Override
public void onViewCreated(@NonNull View v, @Nullable Bundle savedInstanceState) {



    adapter=new CustomRecyclerViewAdapter(timelineDataList);
    recyclerView.setItemViewCacheSize(30);
    recyclerView.setDrawingCacheEnabled(true);
    recyclerView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
    recyclerView.setLayoutManager(new 
    LinearLayoutManager(ctx,LinearLayoutManager.HORIZONTAL,false));
    recyclerView.setAdapter(adapter);

}
 void addTimelineData(String email,String time,String img_link,String caption){
    timelineDataList.add(new TimelineData(email,time,img_link,caption));
    adapter.notifyDataSetChanged():
}
  private  Emitter.Listener handlePosts = new Emitter.Listener(){

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

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

                       demo_time=ob.getString("time");

                       demo_link=ob.getString("img_link");

                       demo_caption=ob.getString("caption");


                       addTimelineData(demo_email,demo_time,demo_link,demo_caption);

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




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