按下按钮后 Kotlin 应用崩溃，并出现 NullPointerException

问：

我正在 Android Studio 中制作一个 Kotlin 应用程序，我可以在其中添加具有卡路里值的食物，例如列表。

它应该如何工作，两个 EditText 组件“etName”和“etCalories”将被传递到一个列表中，然后 RecyclerView 中的 TextView 应该显示它们。

问题是，如果我按下按钮添加项目，应用程序就会崩溃。

这是 logcat

FATAL EXCEPTION: main
    Process: com.example.bbar, PID: 25930
    java.lang.NullPointerException
        at com.example.bbar.ui.home.FoodlistadapterKt.getBinding(foodlistadapter.kt:16)
        at com.example.bbar.ui.home.FoodlistadapterKt.access$getBinding(foodlistadapter.kt:1)
        at com.example.bbar.ui.home.Foodlistadapter.onBindViewHolder(foodlistadapter.kt:57)
        at com.example.bbar.ui.home.Foodlistadapter.onBindViewHolder(foodlistadapter.kt:18)

代码如下

foodlistadapter.kt

package com.example.bbar.ui.home

import android.annotation.SuppressLint
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.example.bbar.R
import android.graphics.Paint.STRIKE_THRU_TEXT_FLAG
import android.widget.TextView
import com.example.bbar.databinding.FooditemBinding


@SuppressLint("StaticFieldLeak")
private var _binding: FooditemBinding? = null
private val binding get() =  _binding!!

class Foodlistadapter(

    private val foods: MutableList<food>
) : RecyclerView.Adapter<Foodlistadapter.foodlistviewholder>() {

    class foodlistviewholder(itemView: View) : RecyclerView.ViewHolder(itemView)

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): foodlistviewholder {
        return foodlistviewholder(
            LayoutInflater.from(parent.context).inflate(
                R.layout.fragment_home,
                parent,
                false
            )
        )
    }

     fun addFood(food: food) {
        foods.add(food)
        notifyItemInserted(foods.size - 1)
    }

     fun deleteFood() {
        foods.removeAll { foods -> foods.isChecked }
        notifyDataSetChanged()

    }

    private fun toggleStrikeThrough(tvFood: TextView, isChecked: Boolean) {
        if (isChecked) {
            tvFood.paintFlags = tvFood.paintFlags or STRIKE_THRU_TEXT_FLAG
        } else {
            tvFood.paintFlags = tvFood.paintFlags or STRIKE_THRU_TEXT_FLAG.inv()
        }
    }

    override fun onBindViewHolder(holder: foodlistviewholder, position: Int) {
        val currentFood = foods[position]
        holder.itemView.apply {
            binding.tvFood.text = currentFood.name
            binding.tvCalories.text= currentFood.calories.toString()
            binding.cbDelete.isChecked = currentFood.isChecked
            toggleStrikeThrough(binding.tvFood, currentFood.isChecked)
            binding.cbDelete.setOnCheckedChangeListener { _, isChecked ->
                toggleStrikeThrough(binding.tvFood, isChecked)
                currentFood.isChecked = !currentFood.isChecked
            }
        }
    }

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

package com.example.bbar.ui.home

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.bbar.R

import com.example.bbar.databinding.FragmentHomeBinding



class HomeFragment : Fragment() {

    private var _binding: FragmentHomeBinding? = null
    private val binding get() = _binding!!

    private lateinit var foodlistadapter: Foodlistadapter

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentHomeBinding.inflate(inflater, container, false)

        return binding!!.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        foodlistadapter = Foodlistadapter(mutableListOf())
        binding.rvFoodItems.adapter = foodlistadapter
        binding.rvFoodItems.layoutManager = LinearLayoutManager(activity)

        binding.bSubmit.setOnClickListener{
            val foodTitle= binding.etName.text.toString()
            val foodCalories = binding.etCalories.text.toString()
            if (foodTitle.isNotEmpty()){
                val food= food(foodTitle, foodCalories.toInt(), false )
                foodlistadapter.addFood(food)
                binding.etName.text.clear()
                binding.etCalories.text.clear()
            }
        }
        binding.bDelete.setOnClickListener{
            foodlistadapter.deleteFood()
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        _binding = null
    }
}

摘要：试图用一个按钮添加具有受人尊敬的卡路里值的食物，但程序崩溃了。