平板电脑用户界面无法在我的应用上运行

I am trying to create an app which has two different UIs for tablets and phones, and I'm using fragments to implement this. I have created two separate xml files for each tablet and phone layout and both are called activity_main.xml, with the phone layout being placed in the res/layout folder and the tablet layout being placed in the res/layout-sw600dp folder.I am trying to create an app which has two diff