[Error] Item size in RecyclerView is different from the size specified in XML

문제

RecyclerView에 들어갈 item의 width를 RecyclerView의 width 사이즈에 맞게(match_parent) 지정했으나, Emulator 또는 실제 핸드폰에는 지정한 사이즈와 다르게 나왔다.

recyclerView.xml

<androidx.recyclerview.widget.RecyclerView
	android:id="@+id/schedule_Listview"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintStart_toStartOf="@id/calendarView"
    app:layout_constraintEnd_toEndOf="@id/calendarView"
    app:layout_constraintTop_toBottomOf="@id/calendarView"
    app:layout_constraintBottom_toTopOf="@id/view"
    tools:ignore="MissingConstraints" />

item.xml

<?xml version="1.0" encoding="utf-8"?>
<layout
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    
    <data>
        <variable
            name="schedule"
            type=".Schedule" />
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="5dp">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"
            android:layout_margin="10dp"
            tools:ignore="MissingConstraints">

            <TextView
                android:id="@+id/title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                android:fontFamily="@font/uhbee_gmin2_bold"
                android:text="@{schedule.content}"
                android:textSize="15sp"
                android:textColor="@color/lightViolet"
                android:textStyle="bold"/>

            <TextView
                android:id="@+id/alarm"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:layout_constraintTop_toBottomOf="@id/title"
                app:layout_constraintStart_toStartOf="parent"
                android:textSize="12sp"
                android:fontFamily="@font/uhbee_gmin2"
                android:text="@{schedule.alarm}"
                android:textColor="@color/lightViolet" />

            <ImageView
                android:id="@+id/importance_img"
                android:layout_width="20dp"
                android:layout_height="20dp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="@id/title"
                app:layout_constraintBottom_toBottomOf="@id/alarm"
                android:scaleType="fitCenter"
                android:background="#00ff0000"/>

        </androidx.constraintlayout.widget.ConstraintLayout>
    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

Adapter.kt

class ScheduleAdapter(private val context: Context) : RecyclerView.Adapter<ScheduleAdapter.Holder>() {

    lateinit var binding : ScheduleItemBinding

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): Holder {
    	val inflater = LayoutInflater.from(context)
        binding = ScheduleItemBinding.inflate(inflater)
        return Holder(binding.root)
    }
    
    ...
    
}

Result

해결

어댑터 클래스에서 뷰 inflate 시 inflate의 전달인자로 LayoutInflater만 보냈었는데, 부모 ViewGroup을 정의해주지 않아서 자식 뷰(item.xml)가 부모 뷰(recyclerView.xml)에 매칭되지 못해서 발생하는 오류였다. 따라서 두번째 전달인자로 parent를 전달하니 오류가 해결되었다.

Adapter.kt

class ScheduleAdapter(private val context: Context) : RecyclerView.Adapter<ScheduleAdapter.Holder>() {

    lateinit var binding : ScheduleItemBinding

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): Holder {
        val inflater = LayoutInflater.from(context)
        binding = ScheduleItemBinding.inflate(inflater, parent, false)
        return Holder(binding.root)
    }
    
    ...
    
}

Result

Reference

https://stackoverflow.com/questions/30691150/match-parent-width-does-not-work-in-recyclerview