有人使用RecyclerView找到了一种方法来设置一个onClickListener的项目在RecyclerView? 我想设置一个监听器为每个项目的布局,但这似乎有点太麻烦了 我确信有一种方法让RecyclerView监听onClick事件,但我不能完全弄清楚。


当前回答

对于kotlin句柄,根据Jacobs的回答单击RecyclerView答案

创建类RecyclerItemClickListener:

class RecyclerItemClickListener(context: Context, recyclerView: RecyclerView, listner: OnItemClickListener) : RecyclerView.OnItemTouchListener {

    var mGestureDetector: GestureDetector
    var mListner: OnItemClickListener
    
    interface OnItemClickListener {
        fun onItemClick(view: View, position: Int)
        fun onLongItemClick(view: View, position: Int)
    }

    init {
        this.mListner = listner
        mGestureDetector = GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
            override fun onSingleTapUp(e: MotionEvent?): Boolean = true
            
            override fun onLongPress(e: MotionEvent?) {
                val child: View? = recyclerView.findChildViewUnder(e!!.getX(), e.getY())
                if (child != null && mListner != null) {
                    mListner.onLongItemClick(child, recyclerView.getChildAdapterPosition(child))
                }
            }
        })
    }

    override fun onTouchEvent(rv: RecyclerView, e: MotionEvent) = Unit

    override fun onInterceptTouchEvent(view: RecyclerView, e: MotionEvent): Boolean {
        val childView: View? = view.findChildViewUnder(e!!.getX(), e.getY())
        if (childView != null && mListner != null && mGestureDetector.onTouchEvent(e)) {
            mListner.onItemClick(childView, view.getChildAdapterPosition(childView))
            return true
        }
        return false
    }

    override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) = Unit

}

点击Any RecyclerView(在活动/片段内):

recyclerView.addOnItemTouchListener(
    RecyclerItemClickListener(this, recyclerView, object : RecyclerItemClickListener.OnItemClickListener {
        override fun onItemClick(view: View, position: Int) {
            // TODO catch click
        }

        override fun onLongItemClick(view: View, position: Int) {
            // TODO catch click
        }
    })
)

其他回答

这是我的自定义适配器的完整代码,这段代码将用XML文件“list_item”中定义的列表项膨胀行,它还将在具有各自位置的所有列表项行上执行单击事件。

public class MyCustomAdapter extends RecyclerView.Adapter`<`AdapterMyCustomAdapter.ViewHolder> {

    public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {
        public onItemClickListener mListener;
        public ViewHolder(View v, onItemClickListener listener) {
            super(v);
            mListener =listener;
            v.setOnClickListener(this);
        }

        @Override
        public void onClick(View v) {
            mListener.onRecyclerItemClick(v, getPosition());
        }

        public static interface onItemClickListener {
            public void onRecyclerItemClick(View view , int position);
        }
    }

    @Override
    public int getItemCount() {
        return 5;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int pos) {      

    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int position) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.list_item, parent, false);

    /* here list_item is an xml file we want to inflate ...it is same as we do in case of listview for customization.*/

        MyCustomAdapter.ViewHolder vh = new ViewHolder(v, new MyCustomAdapter.ViewHolder.onItemClickListener() {

            @Override
            public void onRecyclerItemClick(View view, int position) {
                System.out.println("clicked on list item at position " +position);
            } 
        });
        return vh;
    }
}

我们可以使用Java弱引用来实现这一点。 从语义上讲,视图持有者应该响应click事件或将其委托给正确的响应器。

我们的目标:

Viewholder应该对响应事件的类一无所知,除非它实现了某个接口。 点击处理程序应该得到被点击的视图在RecyclerView中的位置。 我们应该能够辨别视图持有人中单击了哪个视图。 保持所有组件之间的松散耦合,不要造成任何保留周期。

步骤:

Create an interface to handle click responses. Implement this interface in the Activity that will handle the click. Add a member variable in the RecyclerView Adapter to hold the Weak Reference and a constructor that sets it. Do the same in the RecyclerView ViewHolder and add a member variable to keep track of position. Set your on click listeners on any view you'd like in the ViewHolder, then callback to the responder to handle them. Change your onBindViewHolder method to set the position when binding. Pass the responder down to the ViewHolder. In the responder, you can now use getId() on the view to figure out which view was clicked.

这里是一个要点,这样你就可以看到它们是如何组合在一起的: RecyclerView点击处理

让我们看看如何在Jetpack / AndroidX中实现这一点

你需要像这样在viewmodel类中创建一个观察对象

private MutableLiveData<Integer> adapterItem = new MutableLiveData<>();

public MutableLiveData<Integer> getAdapterItem() {
    return adapterItem;
}

public void setAdapterItem(int adapterItem) {
    this.getAdapterItem().setValue(adapterItem);
}

然后在适配器类中,确保将viewmodel引用作为构造函数的参数传递,然后在vieholder上实现clicklistener

    public MyViewHolder(@NonNull View itemView) {
        super(itemView);
        if(itemView != null){
            itemView.setOnClickListener(v -> {
                int adapterPosition = getAdapterPosition();
                viewModel.setAdapterItem(adapterPosition);
            });

        };
    }

然后从活动课上观察变化

    viewModel.getAdapterItem().observe(this, position -> {
        Log.w(TAG, "clicked: " + ridesArray.get(position));
    });

对于kotlin句柄,根据Jacobs的回答单击RecyclerView答案

创建类RecyclerItemClickListener:

class RecyclerItemClickListener(context: Context, recyclerView: RecyclerView, listner: OnItemClickListener) : RecyclerView.OnItemTouchListener {

    var mGestureDetector: GestureDetector
    var mListner: OnItemClickListener
    
    interface OnItemClickListener {
        fun onItemClick(view: View, position: Int)
        fun onLongItemClick(view: View, position: Int)
    }

    init {
        this.mListner = listner
        mGestureDetector = GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
            override fun onSingleTapUp(e: MotionEvent?): Boolean = true
            
            override fun onLongPress(e: MotionEvent?) {
                val child: View? = recyclerView.findChildViewUnder(e!!.getX(), e.getY())
                if (child != null && mListner != null) {
                    mListner.onLongItemClick(child, recyclerView.getChildAdapterPosition(child))
                }
            }
        })
    }

    override fun onTouchEvent(rv: RecyclerView, e: MotionEvent) = Unit

    override fun onInterceptTouchEvent(view: RecyclerView, e: MotionEvent): Boolean {
        val childView: View? = view.findChildViewUnder(e!!.getX(), e.getY())
        if (childView != null && mListner != null && mGestureDetector.onTouchEvent(e)) {
            mListner.onItemClick(childView, view.getChildAdapterPosition(childView))
            return true
        }
        return false
    }

    override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) = Unit

}

点击Any RecyclerView(在活动/片段内):

recyclerView.addOnItemTouchListener(
    RecyclerItemClickListener(this, recyclerView, object : RecyclerItemClickListener.OnItemClickListener {
        override fun onItemClick(view: View, position: Int) {
            // TODO catch click
        }

        override fun onLongItemClick(view: View, position: Int) {
            // TODO catch click
        }
    })
)

对我来说,这是最好的方法:

class YourRecyclerAdapter extends RecyclerView.Adapter<ContactViewHolder> implements View.OnClickListener { 
  ...
  @Override
  public void onClick(View view) {
        int itemPosition = vRecycle.getChildPosition(view);
        //And use itemPosition to get the item from your collection. This way you dont restrain the ViewHolder with a OnClick callback
    }
  ...
}