为什么ImageView会通过增加边距顶部尺寸来变得更小？

Question

I have got a relative Layout in which I want to display one Imageview and one TextView with background-image .

If I didn't use any margin-top it works how I should, but if I increase the top margin of the ImageView the Image gets smaller.

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout                                                                xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/playerNameEnd"
        android:layout_width="200dp"
        android:layout_height="80dp"
        android:background="@drawable/casino2"
        android:gravity="center"
        android:text="Player"
        android:textColor="@color/cream"
        android:textSize="26sp" />

    <ImageView
        android:id="@+id/roulette_EndPic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        app:srcCompat="@drawable/casino" />
</RelativeLayout>
</android.support.constraint.ConstraintLayout>

Answer 1

Use android:paddingTop="40dp"

instead of marginTop