java - 在 Recyclerview 适配器中实现 onClick

Question

1. 我想知道如何为我的每个项目实现 onClick网格(使用 Recycler View 和 Card view)来启动一个新的activity.Below 是我的 ViewHolder 类和 RecyclerView Adapter类

   这是我的 RecyclerView 适配器类

   import android.app.Activity;
   import android.content.Context;
   import android.content.Intent;
   import android.nfc.Tag;
   import android.nfc.TagLostException;
   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;
   
   public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolders> {
   
       private List<ItemObject> itemList;
       private Context context;
   
       public RecyclerViewAdapter(Context context, List<ItemObject> itemList) {
           this.itemList = itemList;
           this.context = context;
       }
   
       @Override
       public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {
   
           View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view_list, null);
           RecyclerViewHolders rcv = new RecyclerViewHolders(layoutView);
           return rcv;
       }
   
       @Override
       public void onBindViewHolder(RecyclerViewHolders holder, final int position) {
           holder.countryName.setText(itemList.get(position).getName());
           holder.countryPhoto.setImageResource(itemList.get(position).getPhoto());
           holder.countryPhoto.setOnClickListener(new View.OnClickListener() {
               @Override
               public void onClick(View view) {
                   Toast.makeText(view.getContext(),"This is Maps",Toast.LENGTH_SHORT).show();
   
               }
           });
       }
   
       @Override
       public int getItemCount() {
           return this.itemList.size();
       }
   }
   
   //This is my Recycler View Holder Class
   
   
   import android.content.Intent;
   import android.support.v7.widget.RecyclerView;
   import android.util.Log;
   import android.view.View;
   import android.widget.ImageView;
   import android.widget.TextView;
   import android.widget.Toast;
   
   public class RecyclerViewHolders extends RecyclerView.ViewHolder implements View.OnClickListener {
   
       public TextView countryName;
       public ImageView countryPhoto;
   
       public RecyclerViewHolders(View itemView) {
           super(itemView);
           itemView.setOnClickListener(this);
           countryName = (TextView) itemView.findViewById(R.id.country_name);
           countryPhoto = (ImageView) itemView.findViewById(R.id.country_photo);
       }
   
       @Override
       public void onClick(View view) {
           Toast.makeText(view.getContext(), "Clicked Country Position = " + getPosition(), Toast.LENGTH_SHORT).show();
   
   
       }
   }
   

Answer 1

我使用接口(interface)作为回调来处理这种情况。

首先，我在 Adapter 中创建了一个接口(interface)类。

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolders> {

    private List<ItemObject> itemList;
    private Context context;
    private ItemClickListener mItemClickListener;

    public RecyclerViewAdapter(Context context, List<ItemObject> itemList) {
        this.itemList = itemList;
        this.context = context;
    }

    @Override
    public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {

        View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view_list, null);
        RecyclerViewHolders rcv = new RecyclerViewHolders(layoutView);
        return rcv;
    }

    public void addItemClickListener(ItemClickListener listener) {
        mItemClickListener = listener;
    }

    @Override
    public void onBindViewHolder(RecyclerViewHolders holder, final int position) {
        holder.countryName.setText(itemList.get(position).getName());
        holder.countryPhoto.setImageResource(itemList.get(position).getPhoto());
        holder.countryPhoto.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (mItemClickListener != null) {
                    mItemClickListener.onItemClick(position);
                }
            }
        });
    }

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

    //Define your Interface method here
    public interface ItemClickListener {
        void onItemClick(int position);
    }
}

然后，让 Activity 或 Fragment 实现该接口(interface)并添加监听器。

public class MyFragment extends Fragment
    implements RecyclerViewAdapter.ItemClickListener {

    private List<ItemObject> mItemList;
    ...
     @Override
    public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
                             final Bundle savedInstanceState) {
       ...
       //Make sure mItemList not NULL
       RecyclerViewAdapter adapter = new RecyclerViewAdapter(getContext(), mItemList);
       //Add Item Click listener
       adapter.addItemClickListener(this);
    }


    @Override
    public void onItemClick(int position) {   
        Toast.makeText(.getContext(),"Click on item: " + position,Toast.LENGTH_SHORT).show();
    }
}

希望这会有所帮助!