Recyclerview适配器与kotlin

在适配器中可以通过两种方式实现项目点击监听器。

第一种方法是使用界面

在你的活动课上:

class YourActivity : AppCompatActivity(), TestAdapter.ClickListener {
...
override fun itemClicked() {

}
...
}

在适配器类中:

class MyAdapter : RecyclerView.Adapter<MyAdapter.MyViewHolder> {
...
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
     holder.textView1.setOnClickListener { 
        clickListener.itemClicked(position) 
     }
}
...
interface ClickListener {
     fun itemClicked(position : Int)
}
...
}

第二种方法是使用callBack调用

在适配器类中:

class MyAdapter(val callBack: (pos:Int) -> Unit) : RecyclerView.Adapter<MyAdapter.MyViewHolder> {
...
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
     holder.textView1.setOnClickListener { 
        callBack(position)
     }
}
}

在你的活动课上:

class YourActivity : AppCompatActivity() {
...
val testAdapter = TestAdapter(
            callBack = { index ->
               
            })
binding.recyclerView.layoutManager = LinearLayoutManager(this)
binding.recyclerView.adapter = testAdapter
...
}

这对我来说很难在活动中有一个项目点击监听器，也有一个项目的单一视图的点击监听器，不会触发项目点击监听器。在玩了Jacob Tabak的回答后，我尊重他的回答，如果项目内没有其他触摸操作，就点击项目。

我有一个自定义OnClickListener接口，有一个项目点击事件，它持有从适配器点击的项目的视图和项目的位置。我在构造函数(或者它可以是setter)中呈现它的一个实例，并将它附加到视图持有者容器click listener。

我也有其他的点击监听器在适配器(可以在视图持有人)，这将处理当前的视图点击从容器。

 public class MyRecyclerAdapter extends RecyclerView.Adapter<MyViewHolder> {

private ArrayList<String> mData;
private OnItemClickListener mOnItemClickListener;

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

public MyRecyclerAdapter(ArrayList<String> itemsData,
        OnItemClickListener onItemClickListener) {
    mOnItemClickListener = onItemClickListener;
    this.mData = itemsData;
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent,
        int viewType) {

    View layoutView = LayoutInflater.from(mContext).inflate(
            R.layout.list_item, parent, false);

    final MyViewHolder viewHolder = new MyViewHolder(layoutView);

    viewHolder.container.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            mOnItemClickListener.onItemClick(v, viewHolder.getAdapterPosition());
        }
    });

    viewHоlder.button.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            //do button click work here with
            // mData.get( viewHolder.getAdapterPosition() );
        }
    });

    return viewHolder;
}

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

在活动中，您需要通过传递OnItemClickListener实例来初始化适配器

public class FeedActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ...

    RecyclerView recyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

    .....

    MyRecyclerAdapter adapter = new MyRecyclerAdapter(new ArrayList<String>(), new OnItemClickListener() {

        @Override
        public void onItemClick(View view, int position) {

            ///list item was clicked
        }
    });

    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setAdapter(mFeedsAdapter);
}

还有我的ViewHolder

public class MyViewHolder extends RecyclerView.ViewHolder {

public Button button;
public View container;

public MyViewHolder(View itemLayoutView) {
    super(itemLayoutView);

    container = itemLayoutView;
    button = (Button) itemLayoutView.findViewById(R.id.button);
}}

这里有一个简单明了的方法是添加到您的ReacyclerView ViewHolder

public static class MyViewholder extends RecyclerView.ViewHolder {

    public MyViewholder(View itemView) {
        super(itemView);

        itemView.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.d("Tag", "onClick：" + getAdapterPosition());
            }
        });

    }
}

getAdapterPosition()返回当前被单击项的位置

将类标记为抽象并实现OnClick方法

public abstract class MainGridAdapter extends
    RecyclerView.Adapter<MainGridAdapter.ViewHolder> {
private List<MainListItem> mDataset;

// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public class ViewHolder extends RecyclerView.ViewHolder {
    // each data item is just a string in this case
    public TextView txtHeader;
    public TextView txtFooter;

    public ViewHolder(View v) {
        super(v);
        txtHeader = (TextView) v.findViewById(R.id.firstLine);
        txtFooter = (TextView) v.findViewById(R.id.secondLine);
    }
}

public void add(int position, MainListItem item) {
    mDataset.add(position, item);
    notifyItemInserted(position);
}

public void remove(MainListItem item) {
    int position = mDataset.indexOf(item);
    mDataset.remove(position);
    notifyItemRemoved(position);
}

// Provide a suitable constructor (depends on the kind of dataset)
public MainGridAdapter(List<MainListItem> myDataset) {
    mDataset = myDataset;
}

// Create new views (invoked by the layout manager)
@Override
public MainGridAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
        int viewType) {
    // create a new view
    View v = LayoutInflater.from(parent.getContext()).inflate(
            R.layout.list_item_grid_line, parent, false);
    // set the view's size, margins, paddings and layout parameters
    ViewHolder vh = new ViewHolder(v);
    return vh;
}

// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
    // - get element from your dataset at this position
    // - replace the contents of the view with that element     
    OnClickListener clickListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            onItemClicked(position);
        }
    };
    holder.itemView.setOnClickListener(clickListener);
    holder.txtHeader.setOnClickListener(clickListener);
    holder.txtFooter.setOnClickListener(clickListener);
    final MainListItem item = mDataset.get(position);
    holder.txtHeader.setText(item.getTitle());
    if (TextUtils.isEmpty(item.getDescription())) {
        holder.txtFooter.setVisibility(View.GONE);
    } else {
        holder.txtFooter.setVisibility(View.VISIBLE);
        holder.txtFooter.setText(item.getDescription());
    }
}

// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
    return mDataset.size();
}

public abstract void onItemClicked(int position);

}

在绑定事件中实现单击处理程序，使其只有一个事件实现

执行此:

mAdapter = new MainGridAdapter(listItems) {         
    @Override
    public void onItemClicked(int position) {
        showToast("Item Clicked: " + position, ToastPlus.STYLE_INFO);
    }
};

同样可以做长时间点击

对我来说，最干净的方法就是这个。

适配器的构造函数

private class EnvironmentTypeRecyclerViewAdapter extends RecyclerView.Adapter<EnvironmentTypeRecyclerViewAdapter.ViewHolder>
{
     private final EnvironmentTypeRecyclerViewAdapterListener mEnvironmentTypeRecyclerViewAdapterListener;
     private List<Environment> mEnvironmentsData;

     public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener
     {
         public ViewHolder(View v)
         {
             super(v);
             v.setOnClickListener(this);

         }

         @Override
         public void onClick(View v)
         {
              Environment environment = mEnvironmentsData.get(getAdapterPosition());
              if (mEnvironmentTypeRecyclerViewAdapterListener != null && environment != null) {
                      mEnvironmentTypeRecyclerViewAdapterListener.onListItemSelected(environment);      
              }
        }

        public EnvironmentTypeRecyclerViewAdapter(List<SmallCellEnvironment> environments, EnvironmentTypeRecyclerViewAdapterListener environmentTypeRecyclerViewAdapterListener)
        {
            mEnvironmentTypeRecyclerViewAdapterListener = environmentTypeRecyclerViewAdapterListener;
            mEnvironmentsData = environments;
        }
}

链接接口

private interface EnvironmentTypeRecyclerViewAdapterListener
{
    void onListItemSelected(Environment environment);
}

我的方式

活动课上:

    public class MyActivity extends AppCompatActivity implements EmployeeAdapter.ClickListener {
    ...
    @Override
    public void onClick(int position) { ... }
    ...
    }

适配器类:

    public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
    ...
    @Override
    public void onBindViewHolder(){
         holder.textView1.setOnClickListener(v -> clickListener.onClick(position));
    }
    ...
    public interface ClickListener {
        void onClick(int position);
    }
    ...
    }