如何從 RecyclerView 對 CardView 項目進行點擊事件

Question

我引用了簡單的 Android RecyclerView 示例來制作Recyclerview項目上的點擊事件。 然后我將這種方式應用於 Recyclerview 中的 CardView，但我失敗了。

ViewHolder 上的 OnClick 事件不起作用。 看起來代碼幾乎相同。 我不知道是什么問題。

我剛剛從Simple Android RecyclerView 示例中復制了代碼

然后將 ArrayList 更改為 ArrayList 另外，我將包含 textview 代碼的 xml 替換為 cardview。

當我將 onClickListener 放在 onBindViewHolder 上時，我成功了該事件。 但我聽說它使應用程序更重。 所以我想避免這種方式。

主活動.java

public class MainActivity extends AppCompatActivity implements MyAdapter.ItemClickListener{

    RecyclerView mRecyclerView;
    MyAdapter mAdapter;
    RecyclerView.LayoutManager mLayoutManager;
    ArrayList<MyData> myDataset;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

        // use this setting to improve performance if you know that changes
        // in content do not change the layout size of the RecyclerView
        mRecyclerView.setHasFixedSize(true);

        // use a linear layout manager
        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        myDataset = new ArrayList<>();
        myDataset.add(new MyData("#InsideOut", R.drawable.a));
        myDataset.add(new MyData("#Mini", R.drawable.b));
        myDataset.add(new MyData("#ToyStroy", R.drawable.c));

        mAdapter = new MyAdapter(this, myDataset);
        mAdapter.setClickListener(this);
        mRecyclerView.setAdapter(mAdapter);
    }
    @Override
    public void onItemClick(View view, int position) {
        Toast.makeText(this, "You clicked " + mAdapter.getItem(position) + " on row number " + position, Toast.LENGTH_SHORT).show();
    }
}

我的適配器

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    private ArrayList<MyData> mDataset;
    private LayoutInflater mInflater;

    private ItemClickListener mClickListener;


    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
        // each data item is just a string in this case
        public ImageView mImageView;
        public TextView mTextView;
        public CardView cv;

        public ViewHolder(View view) {
            super(view);
            mImageView = (ImageView)view.findViewById(R.id.image);
            mTextView = (TextView)view.findViewById(R.id.textview);
            cv = (CardView)view.findViewById(R.id.cardview);
            view.setOnClickListener(this);
        }

        @Override
        public void onClick(View view) {
            if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
            Log.d("이거이거", ""+getAdapterPosition());
        }
    }

    // Provide a suitable constructor (depends on the kind of dataset)
    public MyAdapter(Context context, ArrayList<MyData> myDataset) {
        this.mDataset = myDataset;
        this.mInflater = LayoutInflater.from(context);
    }

    // Create new views (invoked by the layout manager)
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = mInflater.inflate(R.layout.item_cardview, parent, false);
        return new ViewHolder(v);
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        Log.d("position", position+"");

        holder.mTextView.setText(mDataset.get(position).text);
        holder.mImageView.setImageResource(mDataset.get(position).img);

    }

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() {
        return mDataset.size();
    }
    MyData getItem(int id) {
        return mDataset.get(id);
    }

    void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }
    public interface ItemClickListener {
        void onItemClick(View view, int position);
    }
}

class MyData{
    public String text;
    public int img;
    public MyData(String text, int img){
        this.text = text;
        this.img = img;
    }
}

Answer 1

還有一種方法可以做到這一點

 public ViewHolder(final View view) {
        super(view);
        mImageView = (ImageView)view.findViewById(R.id.image);
        mTextView = (TextView)view.findViewById(R.id.textview);
        cv = (CardView)view.findViewById(R.id.cardview);

        cv.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mClickListener != null) mClickListener.onItemClick( view,getAdapterPosition());
            }
        });
}

Answer 2

public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
    // each data item is just a string in this case
    public ImageView mImageView;
    public TextView mTextView;
    public CardView cv;

    public ViewHolder(View view) {
        super(view);
        mImageView = (ImageView)view.findViewById(R.id.image);
        mTextView = (TextView)view.findViewById(R.id.textview);
        cv = (CardView)view.findViewById(R.id.cardview);

      //for whole cardview (If you want to click only card)
      view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //Do the action.
            }
        });

    //if you want to click the only particular item in the CardView
    mImageView .setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               //Do the action.
            }
        });

    }
}

試試這個片段，讓我知道。 如果無法解決，我可以為您解決。

Answer 3

問題是您的interface是adapter class的一部分，而您的onclicklistener是holder class一部分。 您需要從適配器onBindViewHolder調用clicklistener ，為此必須將id賦予itemholder layout file的根布局，並在itemholder constructor按id查找視圖，然后可以按如下所示調用clicklistener。

 @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        Log.d("position", position+"");

        holder.mTextView.setText(mDataset.get(position).text);
        holder.mImageView.setImageResource(mDataset.get(position).img);
        holder.view.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mClickListener.onItemClick(v, position)
        }
    });
    }

Answer 4

只需在您已經添加了此內容的onBindViewHolder中添加以下行即可

cv =（CardView）view.findViewById（R.id.cardview）;

行，以便它起作用或確保您在xml id中給CardView命名為cardview

cv = (CardView)view.findViewById(R.id.cardview);

holder.cv.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mClickListener.onItemClick(v, position)
        }
    });