如何检查 recyclerview 适配器上的空侦听器？

Question

我遇到的问题是，当我单击我的适配器项时，传递给适配器 class 的侦听器为空，因此它永远不会触发任何内容。它确实通过调试告诉我正在点击某些东西。我的 parent class 是新的 kotlin class，适配器是旧的 java class。我已经将 java class 传递给 kotlin，但结果是一样的。

这是我的适配器class

public class CustomersAdapter extends RecyclerView.Adapter<CustomersAdapter.CustomerViewHolder> implements View.OnClickListener {

private List<Customer> customers;
private View.OnClickListener listener;
private CustomersAdapter.OnItemClickListener mListener;

public CustomersAdapter(List<Customer> customer){
    customers = customer;
}

@NonNull
@Override
public CustomerViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.adapter_customers, viewGroup, false);
    v.setOnClickListener(this);
    return new CustomerViewHolder(v,mListener);
}

@Override
public void onBindViewHolder(@NonNull CustomerViewHolder customerViewHolder, int i) {
    customerViewHolder.txtCustomerName.setText(customers.get(i).custName1+" "+customers.get(i).custName2+" "+customers.get(i).custLastName1+" "+customers.get(i).custLastName2);
    customerViewHolder.txtCustomerNickname.setText(customers.get(i).custNickName);
}

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

public void setOnClickListener(View.OnClickListener listener){
    this.listener = listener;
}

public interface OnItemClickListener{
    void onItemSelected(int position);
}

public void setOnItemClickListener(CustomersAdapter.OnItemClickListener listener) {
    mListener = listener;
}

@Override
public void onClick(View v) {
    if(listener != null){
        listener.onClick(v);
    }
}

static class CustomerViewHolder extends RecyclerView.ViewHolder {
    TextView txtCustomerName;
    TextView txtCustomerNickname;
    LinearLayout lytCustomerInfo;

    CustomerViewHolder(View itemView, final CustomersAdapter.OnItemClickListener listener) {
            super(itemView);
        lytCustomerInfo  = itemView.findViewById(R.id.lytCustomerInfo);
        txtCustomerName = itemView.findViewById(R.id.txtNameCustomerAdapter);
        txtCustomerNickname = itemView.findViewById(R.id.txtNicknameCustomerAdapter);
        lytCustomerInfo.setOnClickListener(v -> {
            if (listener != null) {
                int position = getAdapterPosition();
                if (position != RecyclerView.NO_POSITION) {
                    listener.onItemSelected(position);
                }
            }
        });
    }

}

}

我同时制作了 onclicklistener 和 itemclicklistener，其中 none 正在做任何事情。

val customer = Customer()
        customersList = if (filter.trim { it <= ' ' } == "") ArrayList() else customer.getCustomers(filter)

    customersAdapter = CustomersKtAdapter(context, customersList)

    rcvCustomer.adapter = customersAdapter

    customersAdapter.setOnClickListener { v ->
        Log.d("TAG", "message")
    }

    customersAdapter!!.setOnItemClickListener( object: CustomersAdapter.OnItemClickListener {
        override fun onItemSelected(position: Int) {
            Log.d("TAG", "message")
        }
    })

任何帮助或建议都将非常有用，谢谢！

我制作了一个适配器 kotlin class 试图只实现 OnClick 而不是 OnItemClick，但结果是一样的，一旦我点击它，监听器就为 null

class CustomersKtAdapter(applicationContext: Context, customerList: MutableList<Customer>) : RecyclerView.Adapter<CustomersKtAdapter.CustomersKtViewHolder?>(), View.OnClickListener{

private var listener: View.OnClickListener? = null

var context: Context? = null
private var defaultFormat: NumberFormat? = null
var inflater: LayoutInflater? = null

var customerList: List<Customer>? = null

init {
    this.context = applicationContext
    this.customerList = customerList
    defaultFormat = NumberFormat.getCurrencyInstance()
    inflater = LayoutInflater.from(context)
}

override fun onCreateViewHolder(parent: ViewGroup, p1: Int): CustomersKtViewHolder {
    //inflate view
    val v: View = LayoutInflater.from(parent.context).inflate(R.layout.adapter_customers, parent, false)
    v.setOnClickListener(this)
    return CustomersKtViewHolder(v)

}

override fun getItemCount(): Int {
    return customerList!!.size
}

override fun onBindViewHolder(holder: CustomersKtViewHolder, position: Int) {
    holder.txtNicknameCustomerAdapter!!.text = customerList?.get(position)?.custNickName
    holder.txtNameCustomerAdapter!!.text = customerList?.get(position)?.custName1

}

override fun onClick(view: View?) {
    listener?.onClick(view)
}

fun setOnClickListener(listener: View.OnClickListener?) {
    this.listener = listener
}

    class CustomersKtViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
    
    var txtNicknameCustomerAdapter: TextView? = null
    var txtNameCustomerAdapter: TextView? = null

    init {
        txtNicknameCustomerAdapter  = itemView.findViewById(R.id.txtNicknameCustomerAdapter )
        txtNameCustomerAdapter  = itemView.findViewById(R.id.txtNameCustomerAdapter )
    }
}

}

parentclass

    customersAdapter!!.setOnClickListener(View.OnClickListener { v ->
        Log.d("TAG", "message")
    })

Answer 1

你也需要调用mListener

if (position != RecyclerView.NO_POSITION) {
    listener.onItemSelected(position);
    mListener.onItemSelected(position);
}

Answer 2

在设置适配器之前，尝试将 onclicklistener 放在父 class 上

    customersAdapter = CustomersAdapter(customersList)

    customersAdapter!!.setOnClickListener(View.OnClickListener { v ->
        Log.d("TAG", "message")
    })

    rcvCustomer.adapter = customersAdapter

如何检查 recyclerview 适配器上的空侦听器？

How to check for null listener on recyclerview adapter?

android

kotlin

android-recyclerview

onclicklistener

onitemselectedlistener