错误消息：E/RecyclerView：未连接适配器；跳过布局

Question

一切正常，但数据不显示。

但是当我签入“logcat”时，我发现了这个错误消息：

2021-10-20 11:29:37.387 7327-7327/com.example.myplay E/RecyclerView：未连接适配器；跳过布局

2021-10-20 11:29:37.388 7327-7327/com.example.myplay E/RecyclerView：未连接适配器；跳过布局

MainActivity.java：

public class MainActivity extends AppCompatActivity {
    FirebaseDatabase database = FirebaseDatabase.getInstance();
    DatabaseReference myRef = database.getReference();
    private List<DataModel> dataModels;
    private  SliderAdapter sliderAdapter;

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

        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setTitle("Tech Videos");

        FirebaseApp.initializeApp(this);

        SliderView sliderView = findViewById(R.id.sliderView);

        sliderAdapter  = new SliderAdapter(this);
        sliderView.setSliderAdapter(sliderAdapter);
        sliderView.setIndicatorAnimation(IndicatorAnimationType.WORM);
        sliderView.setSliderTransformAnimation(SliderAnimations.SIMPLETRANSFORMATION);
        sliderView.setAutoCycleDirection(SliderView.AUTO_CYCLE_DIRECTION_BACK_AND_FORTH);
        sliderView.setIndicatorSelectedColor(Color.WHITE);
        sliderView.setIndicatorUnselectedColor(Color.GRAY);
        sliderView.setScrollTimeInSec(6);   // 6 sec is slider
        sliderView.setAutoCycle(true);
        sliderView.startAutoCycle();
        renewItems(sliderView);

        loadFirebaseForSlider();
    }

    private void loadFirebaseForSlider() {
        myRef.child("trailer").addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                for(DataSnapshot contentSlider: snapshot.getChildren()){

                    DataModel sliderItem = contentSlider.getValue(DataModel.class);
                    dataModels.add(sliderItem);
                }
                sliderAdapter.notifyDataSetChanged();

            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {
                Toast.makeText(MainActivity.this, "Data can't fetch"+error.getMessage(), Toast.LENGTH_SHORT).show();
                finish();
            }
        });
    }

    public void loadSliderAdapter(){
        sliderAdapter.notifyDataSetChanged();
    }

    public void renewItems(View view) {
        dataModels = new ArrayList<>();
        DataModel dataItems = new DataModel();
        dataModels.add(dataItems);
        sliderAdapter.renewItems(dataModels);
        sliderAdapter.deleteItems(0);
    }
}

DataModel.java：

package com.example.myplay;

public class DataModel {

    private String Ttitle;
    private String Turl;
    private String Tvid;

    public DataModel() {
    }

    public DataModel(String ttitle, String turl, String tvid){
        Ttitle = ttitle;
        Turl = turl;
        Tvid = tvid;
    }

    public String getTtitle() {
        return Ttitle;
    }

    public void setTtitle(String ttitle) {
        Ttitle = ttitle;
    }

    public String getTurl() {
        return Turl;
    }

    public void setTurl(String turl) {
        Turl = turl;
    }

    public String getTvid() {
        return Tvid;
    }

    public void setTvid(String tvid) {
        Tvid = tvid;
    }
}

SliderAdapter.java

package com.example.myplay;

import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.bumptech.glide.Glide;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.tabs.TabLayout;
import com.smarteist.autoimageslider.SliderViewAdapter;

import java.util.ArrayList;
import java.util.List;

public class SliderAdapter extends SliderViewAdapter<SliderAdapter.MyViewHolder> {

     private Context context;


    public SliderAdapter(Context context) {
        this.context = context;
    }

    private List<DataModel> dataModels = new ArrayList<>();

    public void renewItems(List<DataModel> dataModels){

        this.dataModels = dataModels;
        notifyDataSetChanged();
    }
    public void deleteItems(int position){
        this.dataModels.remove(position);
        notifyDataSetChanged();
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent) {

      View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.slider_item,
              parent,false);
        return new MyViewHolder(view);


    }

    @Override
    public void onBindViewHolder(MyViewHolder viewHolder, int position) {

        viewHolder.trailer_title.setText(dataModels.get(position).getTtitle());
        Glide.with(viewHolder.itemView).load(dataModels.get(position).getTurl()).into(viewHolder.slider_image);
        viewHolder.play_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent trailer_video = new Intent(context,PlayerActivity.class);
                trailer_video.putExtra("vid",dataModels.get(position).getTvid());
                trailer_video.putExtra("title",dataModels.get(position).getTtitle());
                v.getContext().startActivity(trailer_video);
            }
        });


    }

    @Override
    public int getCount() {
        return dataModels.size();
    }


     public  class MyViewHolder extends SliderViewAdapter.ViewHolder{
        ImageView slider_image;
        TextView trailer_title;
        FloatingActionButton play_button;


        public MyViewHolder(View itemView) {
            super(itemView);

            slider_image = itemView.findViewById(R.id.image_thumbnail);
            trailer_title = itemView.findViewById(R.id.trailer_title);
            play_button = itemView.findViewById(R.id.floatingActionButton);

        }
    }
}

Answer 1

正如 Alex 所说，您还没有告诉视图使用您创建的适配器，这意味着视图对适配器及其数据一无所知。

要解决此问题，请在 onCreate 中初始化它们之后将适配器设置为视图：

...
SliderView sliderView = findViewById(R.id.sliderView);

sliderAdapter  = new SliderAdapter(this);
...

sliderView.setAdapter(sliderAdapter); // ?