<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >
    <!-- 设置按钮的四个角为弧形 -->
    <!-- android:radius 弧形的半径 -->
    <corners android:radius="20dip" />
    <stroke
        android:width="@dimen/x1"
        android:color="#ffffff" />
</shape>