java - 当我使用实际手机时，RecyclerView 不显示项目 View ，但在模拟器上工作正常

Question

我的 recyclerView 没有显示项目 View ，也不知道为什么，我能够从服务器获取数据，但 recyclerView 只是没有使用 ui 填充我的数据。

这是我的适配器类，它将 itemviews 与数据绑定(bind)在一起:

public class AdapterBooking extends           RecyclerView.Adapter<RecyclerView.ViewHolder>  {

private Context context;
private LayoutInflater inflater;
List<Booking> data= Collections.emptyList();
Booking current ;

public AdapterBooking(Context context,List<Booking> data) {

    this.context = context;
    this.inflater= LayoutInflater.from(context);
    this.data = data;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view=inflater.inflate(R.layout.containerbookings, parent,false);
    MyHolder holder=new MyHolder(view);
    return holder;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder,  int position) {
    MyHolder myHolder = (MyHolder) holder;
     current = data.get(position);

    myHolder.txtAccommoName.setText(current.AccommoName);
    myHolder.txtBookingDate.setText("Booking Date: " + current.BookingDate);
    myHolder.txtBookingExpiry.setText("Booking Expiry: " + current.BookingDuration);
    myHolder.txtBookngStatus.setText("Status " + current.AccredStatus);
    myHolder.txtBookngStatus.setTextColor( ContextCompat.getColor(context, R.color.colorAccent));

    Glide.with(context).load(R.drawable.the_yard_room)
            .placeholder(R.drawable.ic_img_error)
            .error(R.drawable.ic_img_error)
            .into(myHolder.img);
}

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

 class MyHolder extends RecyclerView.ViewHolder {


    TextView txtAccommoName;
    ImageView img;
    TextView txtBookingDate;
    TextView txtBookingExpiry;
    TextView txtBookngStatus;
    BootstrapButton btnCancel;

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

        txtAccommoName = (TextView)itemView.findViewById(R.id.textBookedAccommoName);
        img= (ImageView) itemView.findViewById(R.id.imageBookedAccomo);
        txtBookingDate = (TextView)itemView.findViewById(R.id.txtBookingDate);
        txtBookingExpiry = (TextView)itemView.findViewById( R.id. txtBookingExpiry);
        txtBookngStatus = (TextView)itemView.findViewById( R.id.txtBookingStatus );
        btnCancel   = (BootstrapButton)itemView.findViewById( R.id. btnCancelBookings);

    }

这是我的 Activity 类，它从服务器获取数据:

public class BookingList extends AppCompatActivity {
List<Booking> data;
Booking booking;
RecyclerView recyclerViewBooking;
AdapterBooking mAdapter;

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

    new  Connect().execute();
}


private class Connect extends AsyncTask<String,String,String>
{
    ProgressDialog load;
    HttpURLConnection connection = null;
    URL url = null;
    String http = null;

    SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(BookingList.this);
    int studID = settings.getInt("STUDENT_ID_BOOKING",0 );

    public Connect() {

        load = new ProgressDialog(BookingList.this);

    }


    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        load.setMessage("Loading...");
        load.setCancelable(false);
        load.show();

    }

    @Override
    protected String doInBackground(String... params) {

        http = "http://192.168.42.197:5432/WCF/BookingServices.svc/getAllBookingsByStud/"+studID;
        try {
            url = new URL(http);

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

        try {
            connection = (HttpURLConnection) url.openConnection();
            connection.setReadTimeout(15000);
            connection.setConnectTimeout(10000);
            connection.setRequestMethod("GET");
            connection.setRequestProperty("Accept", "Application/json");
            connection.setDoInput(true);
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            int code = connection.getResponseCode();

            System.out.println("Response: " + code);
            if(code ==HttpURLConnection.HTTP_OK)
            {
                InputStream input =  connection.getInputStream();
                BufferedReader reader = new BufferedReader(new InputStreamReader(input));
                StringBuilder result = new StringBuilder();
                String line = null;

                while((line=reader.readLine()) != null)
                {
                    result.append(line);
                }
                System.out.println(result.toString());

                return (result.toString());

            }else {
                return("Unsuccessful");
            }

        } catch (IOException e) {
            e.printStackTrace();
            return e.toString();
        }finally {
            connection.disconnect();
        }


    }

    @Override
    protected void onPostExecute(String result) {

        load.dismiss();
        load.dismiss();
        data= new ArrayList<>();
        try {

            JSONArray jsonArray = new JSONArray(result);
            for (int i = 0; i < jsonArray.length();i++)
            {
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                JSONObject object = jsonObject.getJSONObject("Accommodation");
                JSONObject objectStudent = jsonObject.getJSONObject("Student");

                booking = new Booking();

                booking.Name = objectStudent.getString("Name");
                booking.Surname = objectStudent.getString("Surname");
                booking.StudentNumber = objectStudent.getInt("StudentNumber");
                booking.AccommoName = object.getString("AccommoName");
                booking.AccredStatus = object.getString("AccredStatus");
                booking.BookingDate = jsonObject.getString("BookingDate");
                booking.BookingDuration = jsonObject.getString("BookingDuration");
                booking.BookingStatus = jsonObject.getString( "BookingStatus" );

                data.add(booking);
            }

            recyclerViewBooking = (RecyclerView)findViewById(R.id.listOfbooks);
            mAdapter = new AdapterBooking(BookingList.this,data);
            recyclerViewBooking.setAdapter(mAdapter);
            recyclerViewBooking.setLayoutManager(new LinearLayoutManager(BookingList.this));

        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(BookingList.this, e.toString(), Toast.LENGTH_LONG).show();
        }


    }
}

}

Answer 1

检查您的布局，确保您的 RecyclerView 不是 ScrollView 的子级。如果您需要，可以使用 NestedScrollView。

如果你设置断点，你的 onBindViewHolder 会起作用吗？

您可以尝试的另一件事:

RecyclerView有一个方法:setHasStableIds(boolean)。

@Override
public void setHasStableIds(boolean hasStableIds) {
    return false;
}

另外，我认为上下文是错误的:

Activity 中:

private Activity getActivity {
    return this;
}

在异步任务中:

mAdapter = new AdapterBooking(getActivity().getApplicationContext(),data);

希望这些信息对您有所帮助。

祝你好运。