如何点击Activity中的recyclerview项目？ [复制]

Question

我使用 recyclerview 创建了图像的水平列表视图，当我单击特定图像时，我想用我的活动图像更改背景图像，但我遇到了问题，我如何设置 onItem click对于我的 mainactivity 中的 recyclerview 项目？

Answer 1

也许它会对你有所帮助，但我确实在我的代码中这样做了：

RecyclerView recyclerView = findViewById(R.id.recycler);
recyclerView.addOnItemTouchListener(
    new RecyclerItemClickListener(context, recyclerView ,new RecyclerItemClickListener.OnItemClickListener() {
      @Override public void onItemClick(View view, int position) {
        // do whatever
      }

      @Override public void onLongItemClick(View view, int position) {
        // do whatever
      }
    })
);

RecyclerItemClickListener 实现：

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;


public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
  private OnItemClickListener mListener;

  public interface OnItemClickListener {
    public void onItemClick(View view, int position);

    public void onLongItemClick(View view, int position);
  }

  GestureDetector mGestureDetector;

  public RecyclerItemClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
    mListener = listener;
    mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return true;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
            if (child != null && mListener != null) {
                mListener.onLongItemClick(child, recyclerView.getChildAdapterPosition(child));
            }
        }
    });
}

  @Override public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
    View childView = view.findChildViewUnder(e.getX(), e.getY());
    if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
      mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
      return true;
    }
    return false;
  }

  @Override public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) { }

  @Override
  public void onRequestDisallowInterceptTouchEvent (boolean disallowIntercept){}
}

Answer 2

   public class MyRecycleViewClickListener implements RecyclerView.OnItemTouchListener {
        private OnItemClickListener mListener;

        public interface OnItemClickListener {
            public void onItemClick(View view, int position);
        }

        GestureDetector mGestureDetector;

        public MyRecycleViewClickListener(Context context, OnItemClickListener listener) {
            mListener = listener;
            mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
                @Override
                public boolean onSingleTapUp(MotionEvent e) {
                    return true;
                }
            });
        }

        @Override
        public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
            View childView = view.findChildViewUnder(e.getX(), e.getY());
            if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
                mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
            }
            return false;
        }

        @Override
        public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
        }

        @Override
        public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

        }
    }

如下使用

mRecyclerView.addOnItemTouchListener(new MyRecycleViewClickListener(this, new MyRecycleViewClickListener.OnItemClickListener() {
    @Override
    public void onItemClick(View view, int position) {

    }
}));

Answer 3

您可以让您的适配器从此适配器扩展：

/**
 * Enables subclasses to add itself as an OnClickListener when binding. This enables the registered
 * listener of type {@link OnItemClickListener} to receive an onItemClick callback.
 */
public abstract class ItemClickRecyclerViewAdapter<VH extends RecyclerView.ViewHolder> extends RecyclerView.Adapter<VH>
    implements View.OnClickListener {

    /**
     * A similar interface to that of ListView lore.
     */
    public interface OnItemClickListener {
        void onItemClick(RecyclerView recyclerView, View view, int position);
    }

    protected WeakReference<RecyclerView> mAttachedRecyclerViewReference;

    protected OnItemClickListener mOnItemClickListener;

    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
        mAttachedRecyclerViewReference = new WeakReference<>(recyclerView);
    }

    @Override
    public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
        super.onDetachedFromRecyclerView(recyclerView);
        mAttachedRecyclerViewReference = null;
    }

    @CallSuper
    @Override
    public void onBindViewHolder(VH holder, int position) {
        holder.itemView.setOnClickListener(this);
    }

    @CallSuper
    @Override
    public void onViewRecycled(VH holder) {
        holder.itemView.setOnClickListener(null);
    }

    /**
     * Provides access to the currently attached recycler view.
     */
    public RecyclerView getAttachedRecyclerView() {
        return mAttachedRecyclerViewReference.get();
    }

    /**
     * Get the registered item click listener.
     */
    public OnItemClickListener getOnItemClickListener() {
        return mOnItemClickListener;
    }

    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        mOnItemClickListener = onItemClickListener;
    }

    @Override
    public void onClick(View v) {
        if (mAttachedRecyclerViewReference != null && mAttachedRecyclerViewReference.get() != null && mOnItemClickListener != null) {
            mOnItemClickListener.onItemClick(mAttachedRecyclerViewReference.get(), v, mAttachedRecyclerViewReference.get().getChildAdapterPosition(v));
        }
    }

并像这样使用它：

MyAdapter adapter = new MyAdapter();
adapter.setOnItemClickListener(this::itemClicked);

private void itemClicked(RecyclerView recyclerView, View view, int position) {
   //Handle item click here
}