Android 带边框的圆角按钮

<?xml version="1.0" encoding="UTF-8"?>  
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">   
<!-- 连框颜色值 --><item>   
  <shape>   
    <solid android:color="#151104" />   
    <corners android:radius="6dp" />    
       
  </shape>   
</item>   
<!-- 主体背景颜色值 -->  
<item android:bottom="1dp" android:right="1dp" android:top="1dp" android:left="1dp">   
     <shape>   
    <gradient android:startColor="#eb6b00" android:centerColor="#ef8000" 
    android:endColor="#f49500" android:type="linear" android:angle="90"  
    android:centerX="0.5" android:centerY="0.5" />  
   
    <padding android:left="2dp" android:top="2dp" android:right="2dp"  
    android:bottom="2dp" />  
   <!-- 应该是圆角 -->
    <corners android:radius="6dp" />    
     </shape>     
</item>  
</layer-list>

<Button
        android:id="@+id/btnSave"
        android:background="@drawable/buttonstyle"
        android:layout_width="match_parent"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:textColor="#ffffff"
        android:textSize="15sp"
        android:height="37dp"       
        android:text="保存" />