-------------------- 1 用 stroke 描邊來實現 ------------------------------------
<shape android:shape="oval">
<stroke android:width="2dp" android:color="#b8c1d1" />
<solid android:color="#ffffff" />
<size android:width="12dp" android:height="12dp" />
</shape>
-------------------- 2 用 layer-list 疊加來實現 ------------------------------------
<layer-list>
<item>
<shape android:shape="oval">
<solid android:color="#c5cedb" />
<size android:width="70dp" android:height="70dp" />
</shape>
</item>
<item android:bottom="17dp" android:left="17dp" android:right="17dp" android:top="17dp">
<shape android:shape="oval">
<solid android:color="@color/white" />
<size android:width="70dp" android:height="70dp" />
</shape>
</item>
</layer-list>
stroke
