Android开发中RecyclerView item点击(二)

其实可以在一篇文章中写完这6种方式,但是我自己的习惯——不喜欢阅读太长的文章,硬生生的被我截断了,其实主要是这几种没有什么联系,分开读也无所谓。继续剩下的3种:
4.定义一个自己的RecyclerView类
见代码:

//初始化
private void init() {
        addOnChildAttachStateChangeListener(new OnChildAttachStateChangeListener() {
            @Override//当子View被添加到Window
            public void onChildViewAttachedToWindow(View view) {
                //此处参数的view就是ItemView
                //这里可以这么实现
                view.setOnClickListener(new View.OnClickListener(){
                    public void onClick(View v){
                        //这里就可以回调自己定义的接口方法了
                    }
                });
            }

            @Override//当子View从Window中移除/解绑
            public void onChildViewDetachedFromWindow(View view) {
                //此处参数的view就是ItemView
                //那么这里我们可以做些什么事了?
                //两种方案:
                //1.啥也不做;
                    // do nothing
                //2.把view的点击事件取消
                view.setOnClickListener(null);
            }
        });
}

出自:http://www.jianshu.com/p/3070695619b9
其实和上一篇是一个人写的,我喜欢简单粗暴,于是直接放了链接,还有这种方法我还没试,明天写个demo试试。
5.RecyclerView 已有的方法 addOnItemTouchListener()+GestureDetectorCompat
(1)为RecyclerView添加addOnItemTouchListener
查看 RecyclerView 源码可以看到, RecyclerView 预留了一个Item的触摸事件方法:

/**
 * Add an {@link OnItemTouchListener} to intercept touch events before they are dispatched
 * to child views or this view's standard scrolling behavior.
 *
 * 

Client code may use listeners to implement item manipulation behavior. Once a listener * returns true from * {@link OnItemTouchListener#onInterceptTouchEvent(RecyclerView, MotionEvent)} its * {@link OnItemTouchListener#onTouchEvent(RecyclerView, MotionEvent)} method will be called * for each incoming MotionEvent until the end of the gesture. * * @param listener Listener to add * @see SimpleOnItemTouchListener */ public void addOnItemTouchListener(OnItemTouchListener listener) { mOnItemTouchListeners.add(listener); }

代码如下:

recyclerView.addOnItemTouchListener(new OnItemTouchListener(recyclerView) {
            @Override
            public void onItemClick(RecyclerView.ViewHolder vh) {
            //item 操作
            }
        });

通过注释我们可知,此方法是在滚动事件之前调用.需要传入一个 OnItemTouchListener 对象. OnItemTouchListener 的代码如下:

public static interface OnItemTouchListener { 

    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e);

    public void onTouchEvent(RecyclerView rv, MotionEvent e);

    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept);
}

第一个是拦截触摸事件的,第二个是处理触摸事件的,第三个是处理触摸冲突的。第三个这里我们用不到,不用管,至于前两个我们只要向下面我们用到的GestureDetectorCompat传递MotionEvent为了获取触摸的坐标,最后再定义个abstract回调。
此接口还提供了一个实现类,且官方推荐使用该实现类 SimpleOnItemTouchListener

/**
 * An implementation of {@link RecyclerView.OnItemTouchListener} that has empty method bodies and
 * default return values.
 * You may prefer to extend this class if you don't need to override all methods. Another
 * benefit of using this class is future compatibility. As the interface may change, we'll
 * always provide a default implementation on this class so that your code won't break when
 * you update to a new version of the support library.
 */
public static class SimpleOnItemTouchListener implements RecyclerView.OnItemTouchListener {
    @Override
    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView rv, MotionEvent e) {
    }

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

在触摸接口中,当触摸时会回调一个 MotionEvent 对象,通过使用 GestureDetectorCompat 来解析用户的操作。
(2)写一个 ItemClickListener
类继承 SimpleOnItemTouchListener
,构造时传入 RecyclerView
对象和Item点击回调,并覆写父类的 boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e)
方法,具体代码如下:

/**
 * 点击事件
 */
public class ItemClickListener extends RecyclerView.SimpleOnItemTouchListener {

    private OnItemClickListener clickListener;
    private GestureDetectorCompat gestureDetector;

    public interface OnItemClickListener {

        void onItemClick(View view, int position);

        void onItemLongClick(View view, int position);
    }

    public ItemClickListener(final RecyclerView recyclerView,
                             OnItemClickListener listener) {
        this.clickListener = listener;
        gestureDetector = 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 && gestureDetector.onTouchEvent(e)) {
                            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) {
        gestureDetector.onTouchEvent(e);
        return false;
    }
}

在 GestureDetectorCompat 的手势回调中我们覆写:

boolean onSingleTapUp(MotionEvent e)
void onLongPress(MotionEvent e)

(3)使用事件监听
在 RecyclerView 的对象中添加 addOnItemTouchListener() 方法,然后在回调中处理你需要的事件:

recyclerView.addOnItemTouchListener(new SingleItemClickListener(recyclerView,
        new SingleItemClickListener.OnItemClickListener() {

            @Override
            public void onItemClick(View view, int position) {
                DevLog.i("touch click name:" + position);
                Toast.makeText(SingleActivity.this, "touch click:" + position, Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onItemLongClick(View view, int position) {
                DevLog.i("touch long click:" + position);
                Toast.makeText(SingleActivity.this, "touch long click:" + position, Toast.LENGTH_SHORT).show();
            }
        }));

6.当 ItemView attach RecyclerView 时实现
代码如下:

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);
    }
}

上面的代码中给 RecyclerView 设置了 OnChildAttachStateChangeListener 事件监听,当子 View attach RecyclerView 时设置事件监听。为了使代码独立简洁,可以写在单独的类中,无论是监听 ItemView 还是ItemView 中每个子 View 的点击事件。

出自;http://www.littlerobots.nl/blog/Handle-Android-RecyclerView-Clicks/

最后,欢迎大家吐槽,共同进步,谢谢。

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