sheishuoAPP/app/res/drawable/btn_rc_transparent.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="false">
        <shape android:shape="rectangle">
            <corners android:radius="15dp"/>
            <stroke android:width="1dp"/>
        </shape>
    </item>
    <item android:state_pressed="true">
        <shape>
            <corners android:radius="15dp" />
            <solid android:width="1dp"
                android:color="@color/colorPrimary" />
        </shape>
    </item>

</selector>