Android 按钮点击带水波纹效果

21版本以下不支持。确保两个文件夹下文件名一致

drawable文件夹：shape_solid_373737_radius_12.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@color/color37" />
    <corners android:radius="12dp" />
</shape>

drawable-v21文件夹：shape_solid_373737_radius_12.xml

<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="@color/color4B">
    <!-- Click -->
    <item android:id="@android:id/mask">
        <shape android:shape="rectangle">
            <solid android:color="@color/color4B" />
            <corners android:radius="12dp" />
        </shape>
    </item>

    <!-- Normal -->
    <item android:id="@android:id/background">
        <shape android:shape="rectangle">
            <solid android:color="@color/color37" />
            <corners android:radius="12dp" />
        </shape>
    </item>

</ripple>