RecyclerviewとRestApi

Question

RestApiでMS SQL Serverのデータを取得しましたが、Recyclerviewに設定できません。私はDataBaseの名前と画像のURLの2つのStringオブジェクトを読んでいます。

私はちょうど Recyclerviewadapter

上のデータを設定することはできません

私を助けたり、私に見せて下さい正しい例

MainActivity.java

public class MainActivity extends AppCompatActivity { 

private List<SingleItemModel> feedsList; 
private RecyclerView mRecyclerView; 
private MyRecyclerViewAdapter adapter; 
private ProgressBar progressBar; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
        .setAction("Action", null).show(); 
     } 
    }); 

    mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view); 
    mRecyclerView.setLayoutManager(new LinearLayoutManager(this)); 
    progressBar = (ProgressBar) findViewById(R.id.progress_bar); 

    new AsyncLoadDeptDetails().execute(); 
} 


protected class AsyncLoadDeptDetails extends 
     AsyncTask<Void, JSONObject, ArrayList<SingleItemModel>> { 
    ArrayList<SingleItemModel> recModel = null; 

    @SuppressWarnings("WrongThread") 
    @Override 
    protected ArrayList<SingleItemModel> doInBackground(Void... params) { 
     // TODO Auto-generated method stub 

     RestAPI api = new RestAPI(); 
     try { 

      JSONObject jsonObj = api.SingleItemModel(); 

      JSONParser parser = new JSONParser(); 
      recModel = parser.parseDepartment(jsonObj); 
      adapter = new MyRecyclerViewAdapter(MainActivity.this, feedsList); 
      mRecyclerView.setAdapter(adapter); 
      feedsList = new ArrayList<>(); 

      for (int i = 0; i < jsonObj.length(); i++) { 
       JSONObject post = jsonObj.optJSONObject(String.valueOf(i)); 
       SingleItemModel item = new SingleItemModel(i); 
       item.setName(post.optString("title")); 
       item.setUrl(post.optString("thumbnail")); 
       feedsList.add(item); 
      } 
     } catch (Exception e) { 
      // TODO Auto-generated catch block 
      Log.d("AsyncLoadDeptDetails", e.getMessage()); 

     } 
     return recModel; 
    } 
    } 
} 

SingleItemModel

public class SingleItemModel { 


private String name; 
private String url; 


public SingleItemModel(String name, String url) { 
    this.name = name; 
    this.url = url; 
} 



public String getUrl() { 
    return url; 
} 

public void setUrl(String url) { 
    this.url = url; 
} 

public String getName() { 
    return name; 
} 

public void setName(String name) { 
    this.name = name; 
} 

}

MyRecyclerViewAdapter

public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.CustomViewHolder> { 
private List<SingleItemModel> singleItemList; 
private Context mContext; 
private OnItemClickListener onItemClickListener; 

public MyRecyclerViewAdapter(Context context, List<SingleItemModel> singleItemList) { 
    this.singleItemList = singleItemList; 
    this.mContext = context; 
} 

@Override 
public CustomViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) { 
    View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.list_row, null); 
    CustomViewHolder viewHolder = new CustomViewHolder(view); 
    return viewHolder; 
} 

@Override 
public void onBindViewHolder(CustomViewHolder customViewHolder, int i) { 
    final SingleItemModel feedItem = singleItemList.get(i); 

    //Download image using picasso library 
    if (!TextUtils.isEmpty(feedItem.getUrl())) { 
     Picasso.with(mContext).load(feedItem.getUrl()) 
       .error(R.drawable.placeholder) 
       .placeholder(R.drawable.placeholder) 
       .into(customViewHolder.imageView); 
    } 

    //Setting text view title 
    customViewHolder.textView.setText(feedItem.getName()); 


    View.OnClickListener listener = new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      onItemClickListener.onItemClick(feedItem); 
     } 
    }; 
    customViewHolder.imageView.setOnClickListener(listener); 
    customViewHolder.textView.setOnClickListener(listener); 
} 

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


class CustomViewHolder extends RecyclerView.ViewHolder { 
    protected ImageView imageView; 
    protected TextView textView; 

    public CustomViewHolder(View view) { 
     super(view); 
     this.imageView = (ImageView) view.findViewById(R.id.thumbnail); 
     this.textView = (TextView) view.findViewById(R.id.title); 
    } 
} 


public OnItemClickListener getOnItemClickListener() { 
    return onItemClickListener; 
} 

public void setOnItemClickListener(OnItemClickListener onItemClickListener) { 
    this.onItemClickListener = onItemClickListener; 
} 

}

Answer 1

private List<SingleItemModel> feedsList; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    feedList = new ArrayList<SingleItemModle>(); 
    adapter = new MyRecyclerViewAdapter(MainActivity.this, feedsList); 
    mRecyclerView.setAdapter(adapter); 

オーバーライドonPostExecuteAsyncTaskの呼び出しadapter.notifyDataSetChanged()あなたはdoInBackgroundにfeedListにアイテムを追加するので。

編集：

SingleItemModel item = new SingleItemModel(); 

へ

変更この

SingleItemModel item = new SingleItemModel(i); 

モデルクラス内のparamとして私を取るコンストラクタがありません。

Answer 2

あなたのコードは正しいですが、feedsListが空のときにアダプタを初期化したため、何も表示されません。何をする必要がonPostExecute（）メソッドをオーバライドし、（暗黙的にdoInBackground後に実行）onPostExecute方法に

adapter = new MyRecyclerViewAdapter(MainActivity.this, feedsList); 
mRecyclerView.setAdapter(adapter); 

次の2行を移動しています。そうすることで、アダプタや別の方法でフィードを渡す前にfeedsListに項目を追加していたでしょう

これが役に立ちます。