Android drawable about the position order of state_pressed= "true" in Selector

There is a button in the interface that uses this style:

<?XML version= "1.0" encoding= "Utf-8"?><selectorxmlns:android= "Http://schemas.android.com/apk/res/android">    <Item>        <Shape>            <CornersAndroid:radius= "10DP"/>            <SolidAndroid:color= "#ff0099ff"/>        </Shape>    </Item>    <Itemandroid:state_pressed= "true">        <Shape>            <CornersAndroid:radius= "5DP"/>            <SolidAndroid:color= "#ff063c91"/>        </Shape>    </Item></selector>

Will find the button is clicked after the color unchanged, the original is press= "true" position upside down, instead, as follows:

<?XML version= "1.0" encoding= "Utf-8"?><selectorxmlns:android= "Http://schemas.android.com/apk/res/android">    <Itemandroid:state_pressed= "true">        <Shape>            <CornersAndroid:radius= "5DP"/>            <SolidAndroid:color= "#ff063c91"/>        </Shape>    </Item>    <Item>        <Shape>            <CornersAndroid:radius= "10DP"/>            <SolidAndroid:color= "#ff0099ff"/>        </Shape>    </Item></selector>

That is, two item tags change position.
In fact, this is a bit like a switch statement, and the last item does not have a property representing the default