边框 xml 文件 semi_circle_layout_border.xml

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

    <!-- background color -->
    <solid android:color="@color/white" />

    <!-- boder width and color -->
    <stroke
        android:width="0.03dp"
        android:color="@color/gray" />

    <padding
        android:bottom="1dp"
        android:left="1dp"
        android:right="1dp"
        android:top="1dp" />

    <!-- corner -->
    <corners android:radius="10dp" />

</shape>

引用边框文件

android:background="@drawable/semi_circle_layout_border"

参考:

https://blog.csdn.net/qq_34589749/article/details/53482659
https://blog.csdn.net/yuxiaohui78/article/details/8274067