RecyclerView Adapter中的OnClickListener未初始化

Question

我正在尝试将OnClickListener添加到回收者视图项目中，但是我一直收到此错误

lateinit property listener has not been initialized

这是我的适配器的外观

class CartAdapter(private val cartItems: List<CartItemEntity>? = null) : RecyclerView.Adapter<CartAdapter.CartViewHolder>() {

    private lateinit var listener: OnItemClickListener

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CartViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.cart_item, parent, false)
        return CartViewHolder(view, cartItems!!, listener)
    }

    override fun getItemCount() = cartItems!!.size

    override fun onBindViewHolder(holder: CartViewHolder, position: Int) {
        val cartItem = cartItems?.get(position)
        holder.productPrice.text = cartItem.productPrice.toInt().toString()
        holder.cart = listOf(cartItem)
    }

    class CartViewHolder(val view: View, var cart: List<CartItemEntity>, listener: OnItemClickListener) : RecyclerView.ViewHolder(view) {
        private val cartRemove: TextView = view.findViewById(R.id.cartRemove)

        init {
            cartRemove.setOnClickListener {
                listener.onItemClick(cart)
            }

        }
    }

    interface OnItemClickListener{
        fun onItemClick(cartItems: List<CartItemEntity>?)
    }

    fun setOnItemClickListener(listener: OnItemClickListener){
        this.listener = listener
    }

}

这是我在片段中实现它的方式

adapter!!.setOnItemClickListener(object : CartAdapter.OnItemClickListener{
            override fun onItemClick(cartItems: List<CartItemEntity>?) {
                Log.e("Cart Item", ""+ cartItems!![0].id)
            }
        })

不确定发生了什么事情

Answer 1

在适配器内创建构造函数

  public Adapter(ListenerAdapter click) {
    this.click = click;
}

并在创建recyclerView时从片段发送对象

private void initRecyclerView(View view) {
    adapter = new Adapter(this);}   

就我而言，我创建View Holder的是另一个类，我也必须将侦听器也发送到ViewHolder，如下所示

 @NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    View view = inflater.inflate(R.layout.item_main_activity, parent, false);
    // we send part of ListenerAdapter to ViewHolder
    return new ViewHolder(view,click);
}