RecyclerView数据插入异常：弹窗提交后无内容显示

我编写了一段代码，用户可通过弹窗输入三项内容，提交后应将数据插入RecyclerView的三列布局中。目前弹窗功能正常，但确认提交后，包含RecyclerView的折叠布局展开却无内容显示。

核心代码 #

// Initialize the RecyclerView
itemList = mutableListOf()
itemAdapter = ItemAdapter(itemList)
binding.dailyRecycler.layoutManager = GridLayoutManager(this, 3)
binding.dailyRecycler.adapter = itemAdapter

binding.dayAdd.setOnClickListener {
    showPopup()
}
}
private fun showPopup() {
    val dialogView = LayoutInflater.from(this).inflate(R.layout.popup_calculate, null)
    val builder = AlertDialog.Builder(this)
        .setView(dialogView)
        .setTitle("Add Item")
        .setPositiveButton("Add") { dialog, which ->
            val itemName = dialogView.findViewById<EditText>(R.id.editTextItem).text.toString()
            val day = dialogView.findViewById<EditText>(R.id.editTextDay).text.toString().toInt()
            val price = dialogView.findViewById<EditText>(R.id.editTextPrice).text.toString().toInt()
            val newItem = Item(itemName, day, price)
            itemList.add(newItem)
            itemAdapter.notifyDataSetChanged()
        }
        .setNegativeButton("Cancel") { dialog, which ->
            dialog.dismiss()
        }
    builder.show()
}
}

RecyclerView适配器代码 #

// RecyclerView adapter
class ItemAdapter(private val itemList: MutableList<Item>) : RecyclerView.Adapter<ItemAdapter.ItemViewHolder>() {
    // ViewHolder class
    inner class ItemViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        private val itemNameTextView: TextView = itemView.findViewById(R.id.itemNameTextView)
        private val dayTextView: TextView = itemView.findViewById(R.id.dayTextView)
        private val priceTextView: TextView = itemView.findViewById(R.id.priceTextView)

        fun bind(item: Item) {
            itemNameTextView.text = item.itemName
            dayTextView.text = item.day.toString()
            priceTextView.text = item.price.toString()
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ItemViewHolder {
        val itemView = LayoutInflater.from(parent.context).inflate(R.layout.calculate_items, parent, false)
        return ItemViewHolder(itemView)
    }

    override fun onBindViewHolder(holder: ItemViewHolder, position: Int) {
        val currentItem = itemList[position]
        holder.bind(currentItem)
    }

    override fun getItemCount() = itemList.size
}

布局文件calculate_items.xml #

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp"
    >

    <TextView
        android:id="@+id/itemNameTextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Item Name"
        android:textSize="16sp"
        android:padding="8dp"
        android:textColor="@color/white"
        />

    <TextView
        android:id="@+id/dayTextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Day"
        android:textSize="16sp"
        android:padding="8dp"/>

    <TextView
        android:id="@+id/priceTextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Price"
        android:textSize="16sp"
        android:padding="8dp"/>


</LinearLayout>

内容的提问来源于stack exchange，提问作者LIM DOU LIANG CALVIN