Recycler Artikel anzeigen onClick

Question

Ich habe eine Reihe von Möglichkeiten gegoogelt, wie man das Objekt erhält, das in einer Recycler-Ansicht angeklickt wird, aber keiner von ihnen scheint zu funktionieren. Der Code unten sollte funktionieren, aber ich verstehe nicht, warum es nicht ist. In Android Studio ist die getPosition() -Methode durchgestrichen. Mir gehen die Ideen aus, gibt es eine Möglichkeit, zumindest auf den Namen der Recycler-Ansicht zu klicken?

ViewHolder

public class ShoppingListViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { 

    public CardView cv; 
    public TextView name; 
    public TextView description; 
    Context context; 

    public ShoppingListViewHolder(View itemView) { 
     super(itemView); 
     cv = (CardView) itemView.findViewById(R.id.cardView); 
     name = (TextView) itemView.findViewById(R.id.title); 
     description = (TextView) itemView.findViewById(R.id.description); 
     itemView.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Log.d("RecyclerView", "onClick：" + getPosition()); 
      } 
     }); 
    } 


    public void bindView(int position) { 

    } 

    @Override 
    public void onClick(View v) { 
     Log.d("TAG", "onClick " + getPosition() + " " + name); 
    } 

Adapter

public class MainShoppingListViewActivity extends AppCompatActivity { 

    List<Data> list = new ArrayList<>(); 
    RecyclerView recyclerView; 
    ShoppingListViewAdapter adapter; 
    Context context; 
    EditText listName; 
    Firebase ref; 


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

     Firebase.setAndroidContext(this); 
     ref = new Firebase("https://shoppinglistshare.firebaseio.com/"); 

     // Getting the recycler view, using the Recycler View 
     recyclerView = (RecyclerView) findViewById(R.id.shopping_list_recycler_view); 
     // The setLayoutManager which contains the main container where the Recycler View is contained 
     recyclerView.setLayoutManager(new LinearLayoutManager(MainShoppingListViewActivity.this)); 

     // Floating action bar initiated, background color is set and then onClickListener to act when the 
     // button is pressed to which the createDialogBox(); method is called 
     FloatingActionButton addFloat = (FloatingActionButton) findViewById(R.id.fab); 
     addFloat.setBackgroundTintList(ColorStateList.valueOf(Color 
       .parseColor("#3F51B5"))); 
     addFloat.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       // Click action 
       createDialogBox(); 
      } 
     }); 
    } 

    /* 
    * This method is used to add a new item to the Recycler View 
    */ 
    public void addNewShoppingListItem(String val) { 
     ref = new Firebase("https://shoppinglistshare.firebaseio.com/"); 

     adapter = new ShoppingListViewAdapter(list, MainShoppingListViewActivity.this); 
     recyclerView.setAdapter(adapter); 

     adapter.addItem(new Data(val, "Created by: Me")); 
     ref.child("List Name: ").setValue(val); 
    } 

    /* 
    * This method is used to add a new item to the Recycler View 
    */ 
    public void removeShoppingListItem(String val) { 
     adapter = new ShoppingListViewAdapter(list, MainShoppingListViewActivity.this); 
     recyclerView.setAdapter(adapter); 

     adapter.addItem(new Data(val, "Created by: Me")); 
    } 

    /* 
    * This method is called inside the float action bar to create a dialog box when the floating action button is pressed. 
    */ 
    public void createDialogBox() { 

     // Alert Dialog Builder 
     AlertDialog.Builder builder = new AlertDialog.Builder(this); 

     // Using Layout Inflater class and assigned to a variable and using getLayout 
     LayoutInflater inflater = this.getLayoutInflater(); 

     // Inflate and set the layout for the dialog 
     // Pass null as the parent view because its going in the dialog layout. 
     // Using the view class to inflate the layout. 
     View rootView = inflater.inflate(R.layout.custom_alert_dialog, null); 
     listName = (EditText) rootView.findViewById(R.id.ShoppinglistName); 

     // Using the AlertDialog Builder created above as "builder" to set the view. 
     builder.setView(rootView) 
       .setPositiveButton("Create", new DialogInterface.OnClickListener() { 
        public void onClick(DialogInterface dialog, int which) { 
         String val = listName.getText().toString(); 
         if (!val.isEmpty()) { 
          addNewShoppingListItem(val); 
         } else { 
          Toast.makeText(MainShoppingListViewActivity.this, "Please enter a value", Toast.LENGTH_SHORT).show(); 
         } 
        } 
       }) 
       // Show the dialog 
       .show(); 
    } 
} 

Logs

FATAL EXCEPTION: main 
Process: familyshopshare.com.familyshopshare, PID: 17889 
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference 
    at android.widget.Toast.<init>(Toast.java:102) 
    at android.widget.Toast.makeText(Toast.java:259) 
    at familyshopshare.com.familyshopshare.ShoppingListViewHolder$1.onClick(ShoppingListViewHolder.java:33) 
    at android.view.View.performClick(View.java:5198) 
    at android.view.View$PerformClick.run(View.java:21147) 
    at android.os.Handler.handleCallback(Handler.java:739) 
    at android.os.Handler.dispatchMessage(Handler.java:95) 
    at android.os.Looper.loop(Looper.java:148) 
    at android.app.ActivityThread.main(ActivityThread.java:5417) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

Answer 1

Kleine Änderungen vorgenommen, hier ist die Lösung, die ich bekam. Ich werde das onClick auf eine andere Methode ändern, anstatt wo es ist. Wenn es irgendwelche Vorschläge sind, wie ich den Code besser machen können lass es mich wissen, jede Beratung ist sehr willkommen :)

public class ShoppingListViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { 

public CardView cv; 
public TextView name; 
public TextView description; 
Context context; 

public ShoppingListViewHolder(View itemView) { 
    super(itemView); 
    cv = (CardView) itemView.findViewById(R.id.cardView); 
    name = (TextView) itemView.findViewById(R.id.title); 
    description = (TextView) itemView.findViewById(R.id.description); 
    itemView.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Data test = new Data(name.getText().toString(), description.getText().toString()); 
      Toast.makeText(v.getContext(), "onClick " + test.getName(), Toast.LENGTH_SHORT).show(); 
      Log.d("RecyclerView", "onClick is this：" + getAdapterPosition()); 
     } 
    }); 
} 

@Override 
public void onClick(View v) { 
    Toast.makeText(context, "onClick " + getAdapterPosition() + " " + name, Toast.LENGTH_SHORT).show(); 
} 

}

Answer 2

Es gibt ein paar Möglichkeiten, wie Sie es tun können. Persönlich mag ich in der Adapterklasse den Hörer in der onBindViewHolder setzen (wo auch immer Sie Ihre viewholder haben):

@Override 
public void onBindViewHolder(ViewHolder holder, int position) { 

    holder.YourTargetObject.setOnClickListener(new View.onClickListener(){ 
     public void onClick(View view){ 
     //do something 
     } 
    }); 

}