为recyclerView添加点击事件

在RecycleView中，并没有直接为Item开放OnItemClick等点击事件，这需要我们自己动手来完成。
下面介绍三中比较常用的方法来实现添加点击事件。

代码下载

在adapter中添加点击事件

比较常见的一种方法。在使用listView时，我们有时候也会使用这种方法来实现添加点击事件。因为在
adapter中添加点击事件的可以实现最item子view点击事件的监控。
思路如下：

在adapter中新建并暴露自己定义的接口类型。

private OnRecyclerViewItemClickListener mOnItenClickListener = null;
private OnRecyclerViewItemLongClickListener mOnItemLongClickListener = null;

public void setOnItemClickListener(OnRecyclerViewItemClickListener listener){
    this.mOnItenClickListener = listener;
}

public void setOnItemLongClickListener(OnRecyclerViewItemLongClickListener listener){
    this.mOnItemLongClickListener = listener;
}

在adapter中添加对指定元素的的点击事件。

v.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            if(mOnItemLongClickListener!=null)
            mOnItemLongClickListener.OnItemLongClickListener(v, (Integer) v.getTag());
            return false;
        }
    });

在接口调用中，调用自己定义的接口来进行实现。

@Override
public void onClick(View v) {
    if(mOnItemLongClickListener !=null)
    mOnItenClickListener.OnItemClickListener(v, (Integer) v.getTag());
}

在activity中调用接口实现监听

mMyAdapter.setOnItemClickListener(new MyAdapter.OnRecyclerViewItemClickListener() {
           @Override
           public void OnItemClickListener(View view, int position) {
               Toast.makeText(MainActivity.this,"通过方法3实现的点击事件"+position,Toast.LENGTH_SHORT).show();
           }
       });
       mMyAdapter.setOnItemLongClickListener(new MyAdapter.OnRecyclerViewItemLongClickListener() {
           @Override
           public void OnItemLongClickListener(View view, int position) {
               Toast.makeText(MainActivity.this,"通过方法3实现的点击事件长安"+position,Toast.LENGTH_SHORT).show();
           }
       });

通过重写GestureDetectorCompat实现监听

虽然RecycleView没有直接实现对应的点击事件，但是在它给我们提供的api中，会发现它还是给我们预留了接口来进行实现
。通过重写GestureDetectorCompat来实现对item点击事件的监控。

 private GestureDetectorCompat gestureDetectorCompat;

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

    public ItemClickListener(final RecyclerView recyclerView,final OnItemClickListener clickListener) {
        gestureDetectorCompat = new GestureDetectorCompat(recyclerView.getContext(),
                new GestureDetector.SimpleOnGestureListener(){
                    @Override
                    public boolean onSingleTapUp(MotionEvent e) {
                        View childView = recyclerView.findChildViewUnder(e.getX(),e.getY());
                        if(childView != null && clickListener!= null){
                            clickListener.onItemClick(childView,recyclerView.getChildAdapterPosition(childView));
                        }
                        return true;
                    }

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

    @Override
    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
        gestureDetectorCompat.onTouchEvent(e);
        return false;
    }

在Activity中进行调用，可以参照下面：

mRecyclerView.addOnItemTouchListener(new ItemClickListener(mRecyclerView, new ItemClickListener.OnItemClickListener() {
   @Override
   public void onItemClick(View view, int position) {
       Toast.makeText(MainActivity.this, "通过方法1实现的点击事件" + position, Toast.LENGTH_SHORT).show();
   }

   @Override
   public void onItemLongClick(View view, int position) {
       Toast.makeText(MainActivity.this, "通过方法1实现的点击事件" + position, Toast.LENGTH_SHORT).show();
   }
}));

利用OnChildAttachStateChangeListener来实现

参照博客http://www.littlerobots.nl/blog/Handle-Android-RecyclerView-Clicks/

package com.hut.reoger.studentsrecycleview.addClickListener;

import android.support.v7.widget.RecyclerView;
import android.view.View;

import com.hut.reoger.studentsrecycleview.R;

/**
 * Created by 24540 on 2017/3/28.
 * 为Item添加点击事件：方法二：利用OnChildAttachStateChangeListener来实现
 * 同时，使用方法，可以实现对item子控件的监听，具体实现参见类：
 * 参考链接：http://www.littlerobots.nl/blog/Handle-Android-RecyclerView-Clicks/
 */

public class ItemClickSupport {
    private final RecyclerView mRecyclerView;
    private OnItemClickListener mOnItemClickListener;
    private OnItemLongClickListener mOnItemLongClickListener;

    private View.OnClickListener mOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mOnItemClickListener != null) {
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                mOnItemClickListener.onItemClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
        }
    };

    private View.OnLongClickListener mOnLongClickListener = new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            if (mOnItemLongClickListener != null) {
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                return mOnItemLongClickListener.onItemLongClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
            return false;
        }
    };

    private RecyclerView.OnChildAttachStateChangeListener mAttachListener
            = new RecyclerView.OnChildAttachStateChangeListener() {
        @Override
        public void onChildViewAttachedToWindow(View view) {
            if (mOnItemClickListener != null) {
                view.setOnClickListener(mOnClickListener);
            }
            if (mOnItemLongClickListener != null) {
                view.setOnLongClickListener(mOnLongClickListener);
            }
        }

        @Override
        public void onChildViewDetachedFromWindow(View view) {}
    };

    private ItemClickSupport(RecyclerView recyclerView) {
        mRecyclerView = recyclerView;
        mRecyclerView.setTag(R.id.item_click_support, this);
        mRecyclerView.addOnChildAttachStateChangeListener(mAttachListener);
    }

    public static ItemClickSupport addTo(RecyclerView view) {
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support == null) {
            support = new ItemClickSupport(view);
        }
        return support;
    }

    public static ItemClickSupport removeFrom(RecyclerView view) {
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support != null) {
            support.detach(view);
        }
        return support;
    }

    public ItemClickSupport setOnItemClickListener(OnItemClickListener listener) {
        mOnItemClickListener = listener;
        return this;
    }

    public ItemClickSupport setOnItemLongClickListener(OnItemLongClickListener listener) {
        mOnItemLongClickListener = listener;
        return this;
    }

    private void detach(RecyclerView view) {
        view.removeOnChildAttachStateChangeListener(mAttachListener);
        view.setTag(R.id.item_click_support, null);
    }

    public interface OnItemClickListener {
        void onItemClicked(RecyclerView recyclerView, int position, View v);
    }

    public interface OnItemLongClickListener {
        boolean onItemLongClicked(RecyclerView recyclerView, int position, View v);
    }
}

在MainActivity监听如下：

  ItemClickSupport.addTo(mRecyclerView).setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
               @Override
               public void onItemClicked(RecyclerView recyclerView, int position, View v) {
                    Toast.makeText(MainActivity.this,"通过方法2实现的点击事件"+position,Toast.LENGTH_SHORT).show();
               }
           });
           ItemClickSupport.addTo(mRecyclerView).setOnItemLongClickListener(new ItemClickSupport.OnItemLongClickListener() {
               @Override
               public boolean onItemLongClicked(RecyclerView recyclerView, int position, View v) {
                   Toast.makeText(MainActivity.this,"通过方法2实现的点击事件长安"+position,Toast.LENGTH_SHORT).show();
                   return false;
               }
           });

用这种方法，也可以实现对item的子view进行监控。具体实现可以参见我的代码。

综上，三种方法都可以实现对item点击事件的监控。
方法1和方法3都可以实现对item的子view实现监听。
方法2可以很方便实现对获取点击位置信息。
方法1附加在adapter中，代码有点耦合，不推荐使用方法1。