Why we need LinearLayout inside of CardView?-CodePudding

I have following xml code from youtube:

<LinearLayout 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="match_parent"
    android:gravity="center"
    tools:context=".MainActivity">

    <androidx.cardview.widget.CardView
        android:layout_width="300dp"
        android:layout_height="300dp"
        app:cardElevation="10dp"
        app:cardCornerRadius="20dp"
        app:cardBackgroundColor="@color/white"
        tools:ignore="MissingConstraints">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">
            <ImageView
                android:layout_height="150dp"
                android:layout_width="match_parent"
                android:src="@drawable/sandwich"
                android:id="@ id/sandwich"
                android:scaleType="centerCrop"
                tools:ignore="MissingConstraints" />
            <TextView
                android:layout_height="wrap_content"
                android:layout_width="match_parent"
                android:text="Welcome"
                android:textAlignment="center" />
        </LinearLayout>

    </androidx.cardview.widget.CardView>
</LinearLayout>

Why we need the LinearLayout that inside the Card component? Can we just inside the Card use ImageView and Text component alone.

CodePudding user response：

CardView is basically a styled FrameLayout source code, thus it doesn't support placing multiple views inside it, unless you want to stack them on each other. So to get around that, you can place a layout that supports multiple views and use it to manage the placement. It doesn't have to be LinearLayout, you can use any available Layout out there.

CodePudding user response：

you have to use another layout in cardview to define background color or image. because cardview doesn't have background feature