java - 可运行的 setClickListener 不起作用

Question

我正在开发一个 Android 应用程序，该应用程序从服务器下载图像并将其显示在回收器 View 中。我在为每个图像启用 onclick 时遇到问题。

在我的MyRecyclerViewAdapterClass中:

public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    public TextView myTextView;
    public ImageView myImage;

    ViewHolder(View itemView) {
        super(itemView);
        myTextView = (TextView) itemView.findViewById(R.id.info_text);
        myImage = (ImageView) itemView.findViewById(R.id.image_test);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
    }
}

    void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }

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

    String getItem(int id){
        return mData[id];
    }
    public void onItemClick(View view, int position){
        Log.i("TAG","You clicked number" + getItem(position));
}

在我的主要 Activity 中:

public void postImage() {
    runOnUiThread(new Runnable() {
        @Override
        public void run() {

            //RecyclerView.
            RecyclerView recyclerView = (RecyclerView) findViewById(R.id.rvNumbers);
            recyclerView.setLayoutManager(new GridLayoutManager(context, numberOfColumns));
            MyRecyclerViewAdapter.ItemClickListener itemClickListener;
            adapter = new MyRecyclerViewAdapter(context,data,file_payload);

            **adapter.setClickListener(this);**
            adapter.mData = data;
            adapter.PAYLOADS = allPayloads;
            adapter.DATES = allDates;
            recyclerView.setAdapter(adapter);

        }
    });}

当我调用adapter.setListener(this)时，出现错误:

setClickListener in my RecyclerView cannot be applied, anonymous.java.lang.Runnable

我尝试在可运行对象中创建一个itemClickListener，如您在代码中看到的那样，使用它来调用adaptersetClickListener(itemClickListener)，但是我收到错误，因为itemClickListener未初始化。

如果我不调用 setClickListener 方法，则 mClickListener 永远不会设置并且始终为 null。调试时，我注意到点击已注册，但没有任何反应，因为 mClickListener 为空。

Answer 1

When I call adapter.setListener(this) I get an error:

因为这里 this 表示您实现的 Runnable 实例，并且您传递的是 Runnable 实例，而不是 MyRecyclerViewAdapter.ItemClickListener > 在适配器中。

我认为您正在尝试将 MyRecyclerViewAdapter.ItemClickListener 实例传递给 ViewHolder。如果我是对的，

为此:

1. 您必须在 MainActivity 中实现 MyRecyclerViewAdapter.ItemClickListener
2. 将该实例传递给适配器。
3. 并从 Adapter 将该实例传递给 ViewHolder。

在主要 Activity 中:

MyRecyclerViewAdapter.ItemClickListener listener = new MyRecyclerViewAdapter.ItemClickListener() {
  @Override
  public void onItemClick(View view, int position) {
     Log.i("TAG","You clicked number" + position);
  }
};

adapter = new MyRecyclerViewAdapter(context,data,file_payload);
adapter. setItemClickListener( listener);

在适配器中

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

ItemClickListener listener;

public void setItemClickListener(ItemClickListener listener){
   this.listener = listener;
}

@Override 
 public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(parent.getContext()).inflate(itemLayout, parent, false);
    ViewHolder viewHolder =  new ViewHolder(v);
    viewHolder.setItemClickListener(listener);
    return viewHolder;
 }

在 ViewHolder 中:

public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView myTextView;
public ImageView myImage;
MyRecyclerViewAdapter.ItemClickListener itemClickListener;

ViewHolder(View itemView) {
    super(itemView);
    myTextView = (TextView) itemView.findViewById(R.id.info_text);
    myImage = (ImageView) itemView.findViewById(R.id.image_test);
    itemView.setOnClickListener(this);
}

@Override
public void onClick(View view) {
    if (itemClickListener != null) itemClickListener.onItemClick(view, getAdapterPosition());
 }


void setItemClickListener(MyRecyclerViewAdapter.ItemClickListener itemClickListener) {
    this.itemClickListener = itemClickListener;
 }


  String getItem(int id){
    return mData[id];
   }
}