错误“RecyclerView：未连接适配器；跳过布局”[重复]

Posted 2023-04-13

【中文标题】错误“RecyclerView：未连接适配器；跳过布局”[重复]

【英文标题】：Error "RecyclerView: No adapter attached; skipping layout" [duplicate]

【发布时间】：2021-01-11 16:19:19

【问题描述】：

我收到以下错误：“RecyclerView: 未连接适配器；跳过布局”但我已连接适配器...我尝试了许多不同的方法，但我无法解决错误.

我正在使用 Volley 库 来获取数据。当我启动活动时，只有进度条可见，直到结束，我收到上面的 Logcat 消息。我在MainActivity 中添加了带有适配器的Recycleview。你能帮帮我吗？

这是我的代码：

MainActivity

public class MainActivity extends AppCompatActivity 
    private RequestQueue mRequestQueue;
    private ArrayList<Earthquake> mEarthquake;
    private RecyclerView mRecycleView;
    private EarthquakeAdapter adapter;
    
    boolean isConnected;
       
    TextView emptyView;
    ProgressBar loadingIndicator;
    
    private static final String USS_REQUEST_URL = "https://earthquake.usgs.gov/fdsnws/event/1/query";
    
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    
        final ConnectivityManager cm = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
    
        Read_network_state(cm);
    
        loadingIndicator = findViewById(R.id.loading_indicator);
        emptyView = findViewById(R.id.empty_view);
    
        mRecycleView = this.findViewById(R.id.recycle_list);
        mRecycleView.setHasFixedSize(true);
        LinearLayoutManager manager = new LinearLayoutManager(this);
        mRecycleView.setLayoutManager(manager);
        mEarthquake = new ArrayList<>();
    
        mRequestQueue = Volley.newRequestQueue(this);
    
        if (isConnected) 
            Uri uri = Uri.parse(USS_REQUEST_URL);
            Uri.Builder buider = uri.buildUpon();
    
            parseEarthquake(buider.toString());
        
    
    
    private void parseEarthquake(String key) 
        final JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, key.toString(), null, response -> 
            double magnitude = Double.parseDouble("");
            String location = "";
            long time = Long.parseLong("");
            String url = "";
    
            try 
                JSONArray feature = response.getJSONArray("feature");
                for (int i = 0; i < feature.length(); i++) 
                    JSONObject features = feature.getJSONObject(i);
                    JSONObject properties = features.getJSONObject("properties");
                    magnitude = properties.getDouble("mag");
                    location = properties.getString("place");
                    time = properties.getLong("time");
                    url = properties.getString("url");
                
    
                Earthquake earthquake = new Earthquake(magnitude, location, time, url);
                mEarthquake.add(earthquake);
    
                adapter = new EarthquakeAdapter(MainActivity.this, mEarthquake);
                mRecycleView.setAdapter(adapter);
    
    
                Log.d("Ruhul", "No adapter");
             catch (JSONException e) 
                e.printStackTrace();
            
        , error -> 
            // Nothing
        );

        mRequestQueue.add(request);
    

    public void Read_network_state(ConnectivityManager connectivityManager) 
        NetworkInfo activeNetwork = connectivityManager.getActiveNetworkInfo();
        if (activeNetwork != null && activeNetwork.isConnectedOrConnecting()) 
            isConnected = true;
            Log.d("Ruhul", "CONNECTED TO INTERNET");
         else 
            isConnected = false;
        
    

    

地震适配器

public class EarthquakeAdapter extends RecyclerView.Adapter<EarthquakeAdapter.MyViewHolder> 
    private Context mContext;
    private List<Earthquake> mData;
    
    public EarthquakeAdapter(Context mContext, List<Earthquake> mData) 
        this.mContext = mContext;
        this.mData = mData;
    
    
    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) 
        View view;
        LayoutInflater inflater = LayoutInflater.from(mContext);
        view = inflater.inflate(R.layout.earthquake_raw, parent, false);
        final MyViewHolder viewHolder = new MyViewHolder(view);
    
        return viewHolder;
    
    
    @Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, int i) 
        Earthquake earthquake = mData.get(i);
        double earthquakeMagnitude = earthquake.getMagnitude();
    
        DecimalFormat decimalFormat = new DecimalFormat("0.0");
        String formattedMagnitude = decimalFormat.format(earthquakeMagnitude);
    
        holder.tvMagnitude.setText(formattedMagnitude);
    
        Date dateObject = new Date(earthquake.getTimeInMilliseconds());
        String formattedDate = formatDate(dateObject);
        holder.tvDate.setText(formattedDate);
    
        String formattedTime = formatTime(dateObject);
        holder.tvTime.setText(formattedTime);
    
        String originalLocation = earthquake.getLocation();
            
        holder.magnitudeCircle = (GradientDrawable) holder.tvMagnitude.getBackground();
    
        int magnitudecolor = getMagnitudeColor(earthquake.getMagnitude());
        holder.magnitudeCircle.setColor(magnitudecolor);
    
        if (originalLocation.contains("of")) 
            String[] parts = originalLocation.split("of");
            holder.tvLocationOffSet.setText(parts[0] + "of");
            holder.tvPrimaryLocation.setText(parts[1]);
         else 
            holder.tvLocationOffSet.setText("Near The");
            holder.tvPrimaryLocation.setText(originalLocation);
        
    
    
    @Override
    public int getItemCount() 
        return mData.size();
    
    
    public static class MyViewHolder extends RecyclerView.ViewHolder 
        TextView tvMagnitude, tvLocationOffSet, tvPrimaryLocation, tvDate, tvTime;
        LinearLayout container;
        GradientDrawable magnitudeCircle;
    
        public MyViewHolder(@NonNull View itemView) 
            super(itemView);
    
            tvMagnitude = itemView.findViewById(R.id.magnitude);
            tvLocationOffSet = itemView.findViewById(R.id.location_offset);
            tvPrimaryLocation = itemView.findViewById(R.id.primary_location);
            tvDate = itemView.findViewById(R.id.date);
            tvTime = itemView.findViewById(R.id.time);
            container = itemView.findViewById(R.id.container);
        
    
    
    /**
     * Return the color of the magitude circle based on the intensity of the earthquake.
     *
     * @param magnitude of the earthquake
     */
    private int getMagnitudeColor(double magnitude) 
        int magnitudeColorResourceId;
        int magnitudeFloor = (int) Math.floor(magnitude);
        switch (magnitudeFloor) 
            case 0:
            case 1:
                magnitudeColorResourceId = R.color.magnitude1;
                break;
    
            case 2:
                magnitudeColorResourceId = R.color.magnitude2;
                break;
    
            case 3:
                magnitudeColorResourceId = R.color.magnitude3;
                break;
    
            case 4:
                magnitudeColorResourceId = R.color.magnitude4;
                break;
    
            case 5:
                magnitudeColorResourceId = R.color.magnitude5;
                break;
    
            case 6:
                magnitudeColorResourceId = R.color.magnitude6;
                break;
    
            case 7:
                magnitudeColorResourceId = R.color.magnitude7;
                break;
    
            case 8:
                magnitudeColorResourceId = R.color.magnitude8;
                break;
    
            case 9:
                magnitudeColorResourceId = R.color.magnitude9;
                break;
    
            default:
                magnitudeColorResourceId = R.color.magnitude10plus;
                break;
        
    
        return ContextCompat.getColor(mContext, magnitudeColorResourceId);
    
    
    private String formatDate(Date dateObject) 
        SimpleDateFormat dateFormat = new SimpleDateFormat("LLL dd, yyyy");

        return dateFormat.format(dateObject);
    
    
    private String formatTime(Date dateObject) 
        SimpleDateFormat timeFormat = new SimpleDateFormat("h:mm a");

        return timeFormat.format(dateObject);
    

    

MainActivity.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_ 
    android:layout_ 
    xmlns:tools="http://schemas.android.com/tools">
        
    <TextView 
        android:id="@+id/empty_view" 
        android:layout_ 
        android:layout_ 
        android:layout_centerInParent="true" 
        android:textAppearance="?android:textAppearanceMedium"/>

    <androidx.recyclerview.widget.RecyclerView 
        android:id="@+id/recycle_list" 
        android:layout_ 
        android:layout_ 
        android:orientation="vertical" 
        tools:listitem="@layout/earthquake_raw"/>
        
    <ProgressBar 
        android:id="@+id/loading_indicator" 
        style="@style/Widget.AppCompat.ProgressBar" 
        android:layout_ 
        android:layout_ 
        android:layout_centerInParent="true"/>
</RelativeLayout>

EarthquakeRaw.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_
    android:layout_
    android:orientation="horizontal"
    android:paddingStart="16dp"
    android:paddingLeft="16dp"
    android:paddingEnd="16dp"
    android:paddingRight="16dp">
    <TextView
        android:id="@+id/magnitude"
        android:layout_
        android:layout_
        android:layout_gravity="center_vertical"
        android:background="@drawable/magnitude_circle"
        android:fontFamily="sans-serif-medium"
        android:gravity="center"
        android:textColor="@android:color/black"
        android:textSize="16sp"
        tools:text="8.9" />

    <LinearLayout
        android:layout_
        android:layout_
        android:layout_gravity="center_vertical"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_weight="1"
        android:orientation="vertical">
        <TextView
            android:id="@+id/location_offset"
            android:layout_
            android:layout_
            android:ellipsize="end"
            android:fontFamily="sans-serif-medium"
            android:maxLines="1"
            android:textAllCaps="true"
            android:textColor="@android:color/black"
            android:textSize="12sp"
            tools:text="30km S of" />

        <TextView
            android:id="@+id/primary_location"
            android:layout_
            android:layout_
            android:ellipsize="end"
            android:maxLines="2"
            android:textColor="@android:color/black"
            android:textSize="12sp"
            tools:text="Long placeholder that should wrap to more than 2 line of text" />
    </LinearLayout>

    <LinearLayout
        android:layout_
        android:layout_
        android:layout_gravity="center_vertical"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:orientation="vertical">
        <TextView
            android:id="@+id/date"
            android:layout_
            android:layout_
            android:layout_gravity="end"
            android:textColor="@color/textColorEarthquakeDetails"
            android:textSize="12sp"
            tools:text="Mar 6, 2010" />

        <TextView
            android:id="@+id/time"
            android:layout_
            android:layout_
            android:layout_gravity="end"
            android:textColor="@color/textColorEarthquakeDetails"
            android:textSize="12sp"
            tools:text="3:00 PM" />
    </LinearLayout>
</LinearLayout>

【参考方案1】：

始终尝试在主 UI 线程中或异步任务之外附加适配器。 此外，您可以在oncreate() 中添加此代码。当mEarthquake arraylist 被填充时，调用adapter.notifydatasetchanged()。

adapter = new EarthquakeAdapter(MainActivity.this, mEarthquake);
            mRecycleView.setAdapter(adapter); 

【参考方案2】：

您应该在 for 循环内向模型添加数据。 像下面这样试试就可以了，

JSONArray feature = response.getJSONArray("feature");
    for (int i = 0; i < feature.length(); i++) 
        JSONObject features = feature.getJSONObject(i);
        JSONObject properties = features.getJSONObject("properties");
        magnitude = properties.getDouble("mag");
        location = properties.getString("place");
        time = properties.getLong("time");
        url = properties.getString("url");
        Earthquake earthquake = new Earthquake(magnitude, location, time, url);
        mEarthquake.add(earthquake);
        adapter = new EarthquakeAdapter(MainActivity.this, mEarthquake);
        mRecycleView.setAdapter(adapter);
        adapter.notifyDatasetChanged();