为什么自定义可绘制对象未显示在android中

Question

TextView已添加到屏幕

<TextView
        android:id="@+id/eventDetail_SpecialInfos"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="4dp"
        android:fontFamily="@font/source_sans_pro"
        android:text="Special Info"
        android:drawableBottom="@drawable/information_underline"
        android:textColor="@color/colorBlack"
        android:textSize="14dp" />

information_underline可绘制为：

<stroke
    android:width="20dp"
    android:color="@color/colorBlack" />

Answer 1

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <size
        android:height="1dp"
        android:width="100dp" />

    <solid android:color="@android:color/black" />

</shape>

Answer 2