[TIL]221205 - CustomList

13주차 실습과 기본 코드는 동일하지만 list 레이아웃을 사용자화했다는 차이가 있음

//item_song.xml
//리스트 각 라인에 대한 레이아웃

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

    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    >

    <ImageView
        android:id="@+id/image"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:src="@android:drawable/ic_menu_gallery"
        android:scaleType="centerCrop"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent" />

    <TextView
        android:id="@+id/text1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:layout_marginStart="16dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toRightOf="@id/image"
        app:layout_constraintRight_toRightOf="parent"/>

    <TextView
        android:id="@+id/text2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toBottomOf="@id/text1"
        app:layout_constraintStart_toStartOf="@id/text1"
        app:layout_constraintRight_toRightOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

---

//SongAdapter class

		<1>
        inner class ViewHolder(itemView: View): RecyclerView.ViewHolder(itemView) {
//            val txTitle: TextView = itemView.findViewById(android.R.id.text1)
//            val txSinger: TextView = itemView.findViewById(android.R.id.text2)
            val txTitle: TextView = itemView.findViewById(R.id.text1)
            val txSinger: TextView = itemView.findViewById(R.id.text2)
        }
        
		<2>
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
            //val view = layoutInflater.inflate(android.R.layout.simple_list_item_2,
            val view = layoutInflater.inflate(R.layout.item_song,
                parent,
                false)
            return ViewHolder(view)
        }

        override fun onBindViewHolder(holder: ViewHolder, position: Int) {
            holder.txTitle.text = model.list.value?.get(position)?.title
            holder.txSinger.text = model.list.value?.get(position)?.singer
            //string인 경우 Elvis 연산자 필요없음 Integer일 때만 필요

        }

<1>

android.R.id.text1 -> R.id.text1

<2>

android.R.layout.simple_list_item_2 -> R.layout.item_song

안드로이드에서 제공하는 레이아웃이 아닌 직접 커스터밍한 레이아웃을 사용하기 때문에