用shape绘制圆形

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android=""
    android:innerRadiusRatio="3"
    android:shape="ring"
    android:thicknessRatio="12"
    android:useLevel="false">
    <!-- <gradient
          android:centerColor="#11FF11"
          android:centerY="0.50"
          android:endColor="#99FF99"
          android:startColor="#008800"
          android:type="sweep"
          android:useLevel="false" />-->

    <gradient
        android:centerColor="#00C45C"
        android:centerY="0.50"
        android:endColor="#ffffff"
        android:startColor="#ffffff"
        android:useLevel="false" />
    <gradient
        android:centerColor="#ffffff"
        android:centerY="0.50"
        android:endColor="#00DD00"
        android:startColor="#ffffff"
        android:useLevel="false" />

</shape>