Retrofit RecyclerView不工作在标签布局

我一直在试图实现在使用改造库显示分析数据的片段内的回收站视图。每当我运行项目时，列表不显示，监视器显示“E/RecyclerView：没有附加适配器;跳过布局”。这里是我的代码： MainActivity：Retrofit RecyclerView不工作在标签布局

package com.example.ahmed.newsapp 

import android.os.Bundle; 
import android.support.v4.view.ViewPager; 
import android.support.v7.app.AppCompatActivity; 
import android.support.design.widget.TabLayout; 

public class MainActivity extends AppCompatActivity { 
private static final String TAG = MainActivity.class.getSimpleName(); 
private static final int ACTIVITY_NUM = 0; 
// TODO - insert your themoviedb.org API KEY here 
private final static String API_KEY = "<API KEY CENSORED>"; 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    // Find the view pager that will allow the user to swipe between fragments 
    ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager); 

    // Create an adapter that knows which fragment should be shown   

    FragmentAdapter adapter = new FragmentAdapter(getSupportFragmentManager 
    ()); 
    // Set the adapter onto the view pager 
    viewPager.setAdapter(adapter); 
    TabLayout ob=(TabLayout) findViewById(R.id.sliding_tabs); 
    ob.setupWithViewPager(viewPager); 
} 
}

FragmentAdapter：

package com.example.ahmed.newsapp; 

import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 

/** 
* Created by ahmed on 3/22/2017. 
*/ 

public class FragmentAdapter extends FragmentPagerAdapter { 
private String tabs[]=new String[]{"Home","Family Members","Colors"}; 
public FragmentAdapter(FragmentManager fm){ 
    super(fm); 
} 

@Override 
public Fragment getItem(int position) { 
    switch(position){ 
     case 0: 
      return new HomeActivity(); 
     case 1: 
      return new HomeActivity(); 
     /* case 2: 
      return new ColorFragment();*/ 
    } 
    return null; 
} 
@Override 
public CharSequence getPageTitle(int position) { 
return tabs[position]; 


} 


@Override 
public int getCount() { 
    return 2; 
} 
}

NewsAdapter：

package com.example.ahmed.newsapp; 



/** 
    * Created by ahmed on 27-08-17. 
    */ 
import android.content.Context; 
import android.support.v7.widget.RecyclerView; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.LinearLayout; 
import android.widget.TextView; 

import java.util.List; 

public class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.NewsViewHolder> { 

private List<News> news; 
private int rowLayout; 
private Context context; 


public static class NewsViewHolder extends RecyclerView.ViewHolder { 
    LinearLayout moviesLayout; 
    TextView movieTitle; 
    TextView data; 
    TextView movieDescription; 
    TextView rating; 


    public NewsViewHolder(View v) { 
     super(v); 
     moviesLayout = (LinearLayout) v.findViewById(R.id.movies_layout); 
     movieTitle = (TextView) v.findViewById(R.id.title); 
     data = (TextView) v.findViewById(R.id.subtitle); 
     movieDescription = (TextView) v.findViewById(R.id.description); 
     rating = (TextView) v.findViewById(R.id.rating); 
    } 
} 

public NewsAdapter(List<News> news, Context context) { 
    this.news = news; 
    // this.rowLayout = rowLayout; 
    this.context = context; 
} 

@Override 
public NewsViewHolder onCreateViewHolder(ViewGroup parent, 
             int viewType) { 
    View view = LayoutInflater.from(parent.getContext()) 
      .inflate(R.layout.list_item_news, parent, false); 
    return new NewsViewHolder(view); 
} 


@Override 
public void onBindViewHolder(NewsViewHolder holder, final int position) { 
    holder.movieTitle.setText(news.get(position).getTitle()); 
    holder.data.setText(news.get(position).getReleaseDate()); 
    holder.movieDescription.setText(news.get(position).getOverview()); 
    holder.rating.setText(news.get(position).getVoteAverage().toString()); 
} 

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

HomeActivity：

package com.example.ahmed.newsapp; 

import android.os.Bundle; 
import android.support.annotation.Nullable; 
import android.support.v4.app.Fragment; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.Toast; 

import java.util.List; 

import retrofit2.Call; 
import retrofit2.Callback; 
import retrofit2.Response; 

import static android.content.ContentValues.TAG; 

public class HomeActivity extends Fragment { 

RecyclerView recyclerView; 
private final static String API_KEY = "<API KEY CENSORED>"; 
NewsAdapter adapter; 
List<News> news,dummy; 
View rootview; 
public HomeActivity() { 
    // Required empty public constructor 
} 
@Nullable 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    rootview = inflater.inflate(R.layout.activity_home, container, false); 

    if (API_KEY.isEmpty()) { 
     Toast.makeText(getContext(), "Please obtain your API KEY first from themoviedb.org", Toast.LENGTH_LONG).show(); 
     return rootview; 
    } 

    ApiInterface apiService = 
      ApiClient.getClient().create(ApiInterface.class); 

    recyclerView = (RecyclerView) rootview.findViewById(R.id.home_page_recycler_view); 
    adapter= new NewsAdapter(dummy,getContext()); 
    Call<NewsResponse> call = apiService.getTopRatedMovies(API_KEY); 
    call.enqueue(new Callback<NewsResponse>() { 

     @Override 
     public void onResponse(Call<NewsResponse> call, Response<NewsResponse> response) { 
      news = response.body().getResults(); 
      adapter.notifyDataSetChanged(); 
      adapter=new NewsAdapter(news,getContext()); 

      recyclerView.setAdapter(adapter); 
      // adapter.setData(news); 
      Log.d(TAG, "Number of movies received: " + news.size()); 
     } 

     @Override 
     public void onFailure(Call<NewsResponse> call, Throwable t) { 
      // Log error here since request failed 
      Log.e(TAG, t.toString()); 
     } 
    }); 
    recyclerView.setHasFixedSize(true); 
    recyclerView.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false)); 
    return rootview; 
} 
}

来源

2017-08-30 Ahmed Husnein Choudhury

是 “获得电影的数目：” 印？ –

使用'if（isVisibleToUser）'变量在'setUserVisibleHint（）'片段的方法上调用API。 – Piyush

你能提供一个关于你的建议@Piyush的代码片段吗？ –

我THI NK问题是在你的FragmentAdapter类

只是从你的FragmentAdapter删除return null;声明如下面的代码

@Override 
public Fragment getItem(int position) { 
    Fragment fragment=null; 
    switch(position){ 
     case 0: 
      fragment= new HomeActivity(); 
     case 1: 
      fragment= new HomeActivity(); 
     /* case 2: 
      return new ColorFragment();*/ 
    } 
    return fragment; 
}

改变这种

recyclerView.setHasFixedSize(true); 
recyclerView.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false)); 
recyclerView = (RecyclerView) rootview.findViewById(R.id.home_page_recycler_view); 
adapter= new NewsAdapter(dummy,getContext());

来源

2017-08-30 10:18:35

这将显示一个错误。 –

@AhmedHusneinChoudhury勾选更新ANS –

还不行的兄弟:( –

你并不需要重新创建适配器的时候，当接受回应。

它可能看起来像：

recyclerView = (RecyclerView) rootview.findViewById(R.id.home_page_recycler_view); 
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity())); 
adapter = new NewsAdapter(null, getActivity()); 
recyclerView.setAdapter(adapter); 
Call<NewsResponse> call = apiService.getTopRatedMovies(API_KEY); 
call.enqueue(new Callback<NewsResponse>() { 

    @Override 
    public void onResponse(Call<NewsResponse> call, Response<NewsResponse> response) { 
     news = response.body().getResults(); 
     adapter.setData(news); 
     Log.d(TAG, "Number of movies received: " + news.size()); 
    } 

    ...

而且在NewsAdapter：

... 

public void setData(Collection<News> newData) { 
    news.clear(); 
    news.addAll(newData); 
    notifyDataSetChanged(); 
} 

@Override 
public int getItemCount() { 
    return news == null ? 0 : news.size(); 
} 

...

来源

2017-08-30 10:28:31

不适用bro：（ –

@AhmedHusneinChoudhury在设置适配器之前忘记添加LayoutManager 尝试在'onCreateViewHolder'中打印一些日志，调用了多少次？确定你在预期的标签中？答案已更新。 –

Retrofit RecyclerView不工作在标签布局

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