Android RecyclerView适配器中的OnClickListener未初始化
我正在尝试将OnClickListener添加到回收器视图项,但我一直收到此错误Android RecyclerView适配器中的OnClickListener未初始化,android,kotlin,android-recyclerview,Android,Kotlin,Android Recyclerview,我正在尝试将OnClickListener添加到回收器视图项,但我一直收到此错误 lateinit property listener has not been initialized 下面是我的适配器的外观 class CartAdapter(private val cartItems: List<CartItemEntity>? = null) : RecyclerView.Adapter<CartAdapter.CartViewHolder>() { p
lateinit property listener has not been initialized
下面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
}
}
class CartAdapter(private val cartItems:List?=null):RecyclerView.Adapter(){
私有lateinit变量侦听器:OnItemClickListener
重写CreateViewHolder(父级:ViewGroup,viewType:Int):CartViewHolder{
val view=LayoutInflater.from(parent.context)。充气(R.layout.cart\u项目,父项,false)
返回CartViewHolder(视图,cartItems!!,侦听器)
}
重写fun getItemCount()=cartItems!!.size
覆盖BindViewHolder(支架:CartViewHolder,位置:Int){
val cartItem=cartItems?获取(位置)
holder.productPrice.text=cartItem.productPrice.toInt().toString()
holder.cart=listOf(cartItem)
}
类CartViewHolder(val视图:视图,var购物车:列表,侦听器:OnItemClickListener):RecyclerView.ViewHolder(视图){
private val cartRemove:TextView=view.findViewById(R.id.cartRemove)
初始化{
cartRemove.setOnClickListener{
listener.onItemClick(购物车)
}
}
}
接口侦听器{
有趣的McClick(cartItems:列表?)
}
有趣的setOnItemClickListener(监听器:OnItemClickListener){
this.listener=listener
}
}
这就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)
}
})
适配器!!。setOnItemClickListener(对象:CartAdapter.OnItemClickListener{
覆盖McClick(cartItems:列表?){
Log.e(“购物车项目”,“购物车项目”![0].id)
}
})
不确定我做错了什么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);}
在我的例子中,我创建了ViewHolder另一个类,我还必须将侦听器发送给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);
}
您可以将侦听器添加为CartAdapter构造函数的一部分
class CartAdapter(private val cartItems: List<CartItemEntity>? = null, itemListener: OnItemClickListener) : RecyclerView.Adapter<CartAdapter.CartViewHolder>() {
private val listener: OnItemClickListener = itemListener
...
interface OnItemClickListener{
fun onItemClick(cartItems: List<CartItemEntity>?)
}
}
class CartAdapter(私有val cartItems:List?=null,itemListener:OnItemClickListener):RecyclerView.Adapter(){
私有val侦听器:OnItemClickListener=itemListener
...
接口侦听器{
有趣的McClick(cartItems:列表?)
}
}
然后从活动中,在初始化适配器时传递侦听器
val adapter = CartAdapter(itemList, object: CartAdapter.OnItemClickListener {
override fun onItemClick(cartItems: List<CartItemEntity>?) {
Log.e("Cart Item", ""+ cartItems!![0].id)
}
})
val adapter=CartAdapter(项目列表,对象:CartAdapter.OnItemClickListener{
覆盖McClick(cartItems:列表?){
Log.e(“购物车项目”,“购物车项目”![0].id)
}
})
嘿,我已经在Kotlin中实现了这一点。仍然会带来同样的问题