使用 dataBinding 在 recyclerView 中获取单击项的位置

Question

thank you for reading my question, I've Implemented onClick in recyclerView using dataBinding but I can send the object itself to click function but I need the item position is it possible to get item position in onClick ? here is how click is implemented in the recyclerView item:

    android:onClick="@{ (v) -> model.click(obj) }"

Answer 1

Use Interface

Create Interface

interface ItemClickListener{
    void itemClicked(int position)
}

Use ItemClickListener and Integer in XML and call interface method on onClick() like this

android:onClick="@{()->itemClickListener.itemClicked(position)}"

Demo XML snippet my_item.xml

<layout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   xmlns:tools="http://schemas.android.com/tools">
   <data>
      <variable
          name="itemClickListener"
          type="ItemClickListener" />
       <variable
          name="position"
          type="Integer"/>
    </data>
    <LinerLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content">
       <ImageView
          android:id="@+id/offer_image"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:onClick="@{()->itemClickListener.itemClicked(position)}"
        />
    </LinearLayout>
</layout>

Set ItemClickListener and Position in Adapter

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {

      private ItemClickListener itemClickListener;

      public MyAdapter(Context){
          itemClickListener = (ItemClickListener)context;
      }

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

          MyItemBinding binding = DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()),
            R.layout.my_item, parent, false);
          return new MyViewHolder(binding);
       }

       @Override
       public void onBindViewHolder(@NonNull OfferViewHolder holder, int position) {
          holder.bind(position);
       }

       class MyViewHolder extends RecyclerView.ViewHolder{

            private MyItemBinding binding;

            public OfferViewHolder(@NonNull ItemOfferBinding binding) {
               super(binding.getRoot());
               this.binding = binding;
            }

            private void bind(int position){
               binding.setItemClickListener(itemClickListener);    //<----This is important
               binding.setPosition(position);                      //<-- This is important
            }

       }

 }

Activity Code

MyActicity extends AppCompatActivity{
      
      MyAdapter adapter = new Adapter(this);
}

Answer 2

 @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        holder.hTextview_Score.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

            }
        });
}

make click of your view in OnBindViewHolder and position is position of view

Answer 3

There is an exposed property that you can use inside ViewHolder, when using databinding. Just call adapterPosition .

Answer 4

You can use adapterPosition in view holder to pass item position to ItemView and then you can pass itemPosition to android:onClick="@{ (v) -> model.click(obj, itemPosition) }"

 class GeneralHolder<DataModel, ClickListner>(
        private val binding: ViewDataBinding,
        val listener: ClickListner
    ) :
        RecyclerView.ViewHolder(binding.root) {
        fun bind(data: DataModel) {
            binding.setVariable(BR.item, data)
            binding.setVariable(BR.presenter, listener)
            binding.setVariable(BR.itemPosition, adapterPosition)
            binding.executePendingBindings()
        }
    }