I'm trying to build a custom menu screen for my Android app through using a RecyclerView. However, when I try to create a MenuItem for my ArrayList, the app crashes when I try to open activity_menu.xml screen. How would I make it to where the options_menu.xml populate the activity_menu.xml RecyclerView? Thank you!

My end result

What I have

activity_menu.xml

<androidx.recyclerview.widget.RecyclerView
    android:id="@ id/menuRecyclerView"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:layout_marginStart="12dp"
    android:layout_marginTop="12dp"
    android:layout_marginEnd="12dp"
    android:layout_marginBottom="12dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@ id/view" />

MenuActivity.kt

class MenuActivity : AppCompatActivity() {

    lateinit var menuAdapter: MenuAdapter
    val menuList = ArrayList<MenuItem>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_menu)

        createMenu()
    }

    private fun createMenu() {

        menuAdapter = MenuAdapter(this, menuList)

        val menuRecycleView = findViewById<RecyclerView>(R.id.menuRecyclerView)
        menuRecycleView.apply {
            layoutManager = LinearLayoutManager(this@MenuActivity, LinearLayoutManager.VERTICAL, false)
            adapter = menuAdapter
            setHasFixedSize(true)
        }

    }

}

options_meny.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@ id/menu1"
        android:icon="@drawable/outline_person_"
        android:title="@string/my_profile" />

    <item
        android:id="@ id/menu2"
        android:icon="@drawable/bookings_"
        android:title="@string/my_bookings" />

    <item
        android:id="@ id/menu3"
        android:icon="@drawable/payment_"
        android:title="@string/payment" />

    <item
        android:id="@ id/menu4"
        android:icon="@drawable/on_going_jobs_"
        android:title="@string/on_going_jobst" />

    <item
        android:id="@ id/menu5"
        android:icon="@drawable/settings_"
        android:title="@string/settings" />
    
</menu>

item_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.card.MaterialCardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="50dp">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@ id/iconImageButton"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_marginStart="16dp"
            android:background="@drawable/circle_shape"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            tools:ignore="TouchTargetSizeCheck,SpeakableTextPresentCheck" />

        <ImageView
            android:id="@ id/iconImageView"
            android:layout_width="15dp"
            android:layout_height="15dp"
            android:elevation="10dp"
            app:layout_constraintBottom_toBottomOf="@ id/iconImageButton"
            app:layout_constraintEnd_toEndOf="@ id/iconImageButton"
            app:layout_constraintStart_toStartOf="@ id/iconImageButton"
            app:layout_constraintTop_toTopOf="@ id/iconImageButton"
            app:srcCompat="@drawable/profile_photo_"
            android:contentDescription="@string/string_menu_icon_image" />

        <TextView
            android:id="@ id/menuLabelTextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="16dp"
            android:text="@string/menu_label"
            android:textAllCaps="false"
            android:textColor="@color/black"
            android:textSize="12sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toEndOf="@ id/iconImageButton"
            app:layout_constraintTop_toTopOf="parent" />

        <ImageView
            android:id="@ id/menuArrowImageView"
            android:layout_width="15dp"
            android:layout_height="15dp"
            android:layout_marginEnd="16dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:srcCompat="@drawable/right_chevron_"
            android:contentDescription="@string/menu_arrow" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</com.google.android.material.card.MaterialCardView>

MenuItem.kt

class MenuItem constructor(val menuName: String = "", val menuImage: String = "")

MenuAdapter.kt

class MenuAdapter(var context: Context, var list: ArrayList<MenuItem>) : RecyclerView.Adapter<MenuAdapter.MyViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        val v = LayoutInflater.from(parent?.context).inflate(R.layout.menu_item, parent, false)
        return MyViewHolder(v)
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        holder?.bindItems(list[position])
    }

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

    class MyViewHolder(view: View) : RecyclerView.ViewHolder(view){

        fun bindItems(items: MenuItem) {
            val menuName = itemView.findViewById<TextView>(R.id.menuLabelTextView)
            val menuImage = itemView.findViewById<ImageView>(R.id.iconImageView)

            menuName.text = items.menuName
            Picasso.get().load(items.menuImage).into(menuImage)
        }
    }
}

CodePudding user response：

Actually you haven't added any item to your list yet, and based on that the recycler view doesn't show anything because the item count of it's adapter is zero