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

不幸的是,RecyclerView缺少ListView内置的几个功能。 例如,添加OnItemClickListener的能力,当一个项目被单击时触发。 RecyclerView允许你在适配器中设置一个OnClickListener,但是传递那个点击 从你的调用代码,到适配器,再到ViewHolder,监听器是复杂的 要捕捉一个简单的项目单击。

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);
}
}

您还需要定义R.id。使用ids.xml:

 <?xml version="1.0" encoding="utf-8"?>
 <resources>
  <item name="item_click_support" type="id" />
 </resources>

结果代码点击侦听器现在看起来像这样:

ItemClickSupport.addTo(mRecyclerView).setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
@Override
public void onItemClicked(RecyclerView recyclerView, int position, View v) {
    // do it
}
});

关于recyclerview点击的简要说明,请看看这个littlerobots_blog

其他回答

我知道有很多答案,但我想我也可以提供我的实现。(完整的细节可以在我回答的另一个问题中找到)。

所以,要添加一个点击监听器,你的内部ViewHolder类需要实现View.OnClickListener。这是因为你将设置一个OnClickListener到ViewHolder的构造函数的itemView参数。让我来告诉你我的意思:

public class ExampleClickViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    TextView text1, text2;

    ExampleClickViewHolder(View itemView) {
        super(itemView);

        // we do this because we want to check when an item has been clicked:
        itemView.setOnClickListener(this);

        // now, like before, we assign our View variables
        title = (TextView) itemView.findViewById(R.id.text1);
        subtitle = (TextView) itemView.findViewById(R.id.text2);
    }

    @Override
    public void onClick(View v) {
        // The user may not set a click listener for list items, in which case our listener
        // will be null, so we need to check for this
        if (mOnEntryClickListener != null) {
            mOnEntryClickListener.onEntryClick(v, getLayoutPosition());
        }
    }
}

唯一需要添加的其他东西是适配器的自定义接口和setter方法:

private OnEntryClickListener mOnEntryClickListener;

public interface OnEntryClickListener {
    void onEntryClick(View view, int position);
}

public void setOnEntryClickListener(OnEntryClickListener onEntryClickListener) {
    mOnEntryClickListener = onEntryClickListener;
}

这样,新的支持单击的适配器就完成了。

现在,让我们用它…

    ExampleClickAdapter clickAdapter = new ExampleClickAdapter(yourObjects);
    clickAdapter.setOnEntryClickListener(new ExampleClickAdapter.OnEntryClickListener() {
        @Override
        public void onEntryClick(View view, int position) {
            // stuff that will happen when a list item is clicked
        }
    });

这基本上就是设置普通适配器的方法,除了使用您创建的setter方法来控制当用户单击特定列表项时要做什么。

你也可以看看我在GitHub上做的一组关于Gist的例子:

https://gist.github.com/FarbodSalamat-Zadeh/7646564f48ee708c1582c013e1de4f07

很简单,添加这个类:

public class OnItemClickListener implements View.OnClickListener {
    private int position;
    private OnItemClickCallback onItemClickCallback;

    public OnItemClickListener(int position, OnItemClickCallback onItemClickCallback) {
        this.position = position;
        this.onItemClickCallback = onItemClickCallback;
    }

    @Override
    public void onClick(View view) {
        onItemClickCallback.onItemClicked(view, position);
    }

    public interface OnItemClickCallback {
        void onItemClicked(View view, int position);
    }
}

获取一个'OnItemClickCallback'接口实例,并把它放在你的activity或fragment中:

private OnItemClickListener.OnItemClickCallback onItemClickCallback = new OnItemClickListener.OnItemClickCallback() {
    @Override
    public void onItemClicked(View view, int position) {
    }
};

然后,将这个回调传递给你的recyclerView:

recyclerView.setAdapter(new SimpleStringRecyclerViewAdapter(Arrays.asList("1", "2", "3"), onItemClickCallback));

最后,这将是你的适配器:

public class SimpleStringRecyclerViewAdapter extends RecyclerView.Adapter<SimpleStringRecyclerViewAdapter.ViewHolder> {
    private List<String> mValues;
    private OnItemClickListener.OnItemClickCallback onItemClickCallback;

    public SimpleStringRecyclerViewAdapter(List<String> items, OnItemClickListener.OnItemClickCallback onItemClickCallback) {
        mValues = items;
        this.onItemClickCallback = onItemClickCallback;
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public final TextView mTextView;

        public ViewHolder(View view) {
            super(view);
            mTextView = (TextView) view.findViewById(R.id.txt_title);
        }
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(final ViewHolder holder, final int position) {
        holder.mTextView.setText(mValues.get(position));
        holder.mTextView.setOnClickListener(new OnItemClickListener(position, onItemClickCallback));
    }

    @Override
    public int getItemCount() {
        return mValues.size();
    }
}

在Kotlin中也是如此

inner class MyViewHolder(v: View, myOnClickListener: MyOnClickListener) : RecyclerView.ViewHolder(v) {
    init {
        v.setOnClickListener { v -> myOnClickListener.onClick(v, adapterPosition) }
    }
}

override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): MyViewHolder {
    val view = LayoutInflater.from(viewGroup.context).inflate(R.layout.myview, viewGroup, false)
    return MyViewHolder(view, mOnClickListener)
}

inner class MyOnClickListener {
    fun onClick(view: View, position: Int) {
        val item = mList[position]
        Toast.makeText(view.context, item, Toast.LENGTH_LONG).show()
    }
}

基于Jacob Tabak的回答(+1),我能够添加onLongClick监听器:

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

        void onItemLongClick(View view, int position);
    }

    private OnItemClickListener mListener;

    private 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 childView = recyclerView.findChildViewUnder(e.getX(), e.getY());

                if (childView != null && mListener != null) {
                    mListener.onItemLongClick(childView, recyclerView.getChildAdapterPosition(childView));
                }
            }
        });
    }

    @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) {
    }
}

然后你可以这样使用它:

recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(getActivity(), recyclerView, new RecyclerItemClickListener.OnItemClickListener() {
    @Override
    public void onItemClick(View view, int position) {
        // ...
    }

    @Override
    public void onItemLongClick(View view, int position) {
        // ...
    }
}));

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));
    });