從RecyclerView適配器調用過渡動畫而不是活動

Question

我有一個應用程序，裏面充滿了一些卡片，在我製作的自定義RecyclerView（RV）適配器的幫助下，充滿了RecyclerView。 然後我試圖按照this tutorial來添加活動之間的轉換。但是，如教程中所示，在Activity中創建Intent時會調用動畫，並且我的OnClick代碼位於RVAdapter中。這使我對法

Intent intent = new Intent(HomeActivity.this, TargetActivity.class); 
intent.putExtra(TargetActivity.ID, Contact.CONTACTS[position].getId()); 
ActivityOptionsCompat options = ActivityOptionsCompat.makeSceneTransitionAnimation(
     // the context of the activity 
     MainActivity.this, 

     // For each shared element, add to this method a new Pair item, 
     // which contains the reference of the view we are transitioning *from*, 
     // and the value of the transitionName attribute 
     new Pair<View, String>(view.findViewById(R.id.CONTACT_circle), 
       getString(R.string.transition_name_circle)), 
     new Pair<View, String>(view.findViewById(R.id.CONTACT_name), 
       getString(R.string.transition_name_name)), 
     new Pair<View, String>(view.findViewById(R.id.CONTACT_phone), 
       getString(R.string.transition_name_phone)) 
); 
ActivityCompat.startActivity(HomeActivity.this, intent, options.toBundle()); 

我試圖將活動對象傳遞給在其構造方法的RVAdapter所需的活動沒有進入，但它只能導致NullPointerException異常。

這裏是我的RVAdapter代碼：

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.AppVH>{ 


ArrayList<App> apps; 

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

@Override 
public void onBindViewHolder(AppVH holder, int position) { 
    holder.name.setText(apps.get(position).getName()); 
    holder.artist.setText(apps.get(position).getArtist()); 
    String p = ""; 
    if(apps.get(position).getPrice()==0.0) p="Free"; 
    else p= "$"+apps.get(position).getPrice()+" "+apps.get(position).getCurrency(); 
    holder.price.setText(p); 
    Picasso.with(AppListActivity.context).load(apps.get(position).getUrlImLarge()).into(holder.icon); 
} 

@Override 
public int getItemCount() { 
    return apps.size(); 
} 
@Override 
public void onAttachedToRecyclerView(RecyclerView recyclerView) { 
    super.onAttachedToRecyclerView(recyclerView); 
} 

RecyclerViewAdapter(ArrayList<App> applications){ 
    this.apps = applications; 
} 

// Clean all elements of the recycler 
public void clear() { 
    apps.clear(); 
    notifyDataSetChanged(); 
} 

// Add a list of items 
public void addAll(ArrayList<App> list) { 
    apps.addAll(list); 
    notifyDataSetChanged(); 
} 

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

    CardView cv; 
    TextView name; 
    TextView artist; 
    TextView price; 
    ImageView icon; 
    private final Context c; 

    public AppVH(View itemView) { 
     super(itemView); 
     cv = (CardView) itemView.findViewById(R.id.cardview); 
     name = (TextView) itemView.findViewById(R.id.app_name); 
     artist = (TextView) itemView.findViewById(R.id.app_artist); 
     price = (TextView) itemView.findViewById(R.id.app_price); 
     icon = (ImageView) itemView.findViewById(R.id.app_icon); 
     itemView.setOnClickListener(this); 
     c = itemView.getContext(); 
    } 

    @Override 
    public void onClick(View v) { 
     final Intent intent; 
     Log.d("Debugtext","Card with position " + getAdapterPosition() + " was touched."); 
     intent = new Intent(c, AppDetailActivity.class); 
     intent.putExtra("app",apps.get(getAdapterPosition())); 
     c.startActivity(intent); 
    } 
} 
} 

以下是我的適配器添加到RecyclerView在我的 「HomeActivity」。

RecyclerView rv = (RecyclerView) findViewById(R.id.recycler_view); 

    rv.setHasFixedSize(true); 
    GridLayoutManager gridlm = new GridLayoutManager(getApplicationContext(),columns); 
    rv.setLayoutManager(gridlm); 
    rvadapter = new RecyclerViewAdapter(apps); 
    rv.setAdapter(rvadapter); 

是否有一種簡單的方法來從Adapter中調用ActivityCompat.startActivity（...）方法？

Answer 1

因此，我做了一件非常簡單的事情：我將上下文作爲一項活動進行鑄造。哇。

 @Override 
     public void onClick(View v) { 
      final Intent intent; 
      //Opens the AppDetailActivity showing the selected App Card 
      //Log.d("Debugtext","Card with position " + getAdapterPosition() + " was touched."); 
      intent = new Intent(c, AppDetailActivity.class); 
      intent.putExtra("app",apps.get(getAdapterPosition())); 

      ActivityOptionsCompat options = ActivityOptionsCompat. 
        makeSceneTransitionAnimation((Activity)c, (View)cv, "appcard"); 
      c.startActivity(intent, options.toBundle()); 
     }