Here my layout xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/catalog_item_card_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
card_view:cardCornerRadius="5dp"
card_view:cardUseCompatPadding="true">
<android.support.constraint.ConstraintLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="@+id/imageViewPhoto"
android:layout_width="wrap_content"
android:layout_height="160dp"
android:src="@drawable/test_merchant_preview"
card_view:layout_constraintLeft_toLeftOf="parent"
card_view:layout_constraintRight_toRightOf="parent"
card_view:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
</android.support.v7.widget.CardView>
Here result on Andrdoid 5.0+
As you can see the ImageView success show with radius. OK.
Now I run app on Android 4.3.
And here result:
As you can see the ImageView show without radius. Why?