android shape绘制半圆

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"android:shape="rectangle"><sizeandroid:width="20dp"android:height="10dp" /><solid android:color="#FFFFFF" /><cornersandroid:bottomLeftRadius="30dp"android:bottomRightRadius="30dp"android:topLeftRadius="0dp"android:topRightRadius="0dp" />
</shape>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"android:shape="rectangle"><sizeandroid:width="10dp"android:height="20dp" /><solid android:color="#FFFFFF" /><cornersandroid:bottomLeftRadius="30dp"android:bottomRightRadius="0dp"android:topLeftRadius="30dp"android:topRightRadius="0dp" />
</shape>