将设备类型更改为10'平板电脑（布局编辑器左上角第2个选项）使屏幕足够大，可以让所有设置都可以***地滚动。
做你的事情，然后恢复正常的大小。

Has anyone figured out how to scroll the contents of the Layout Editor when those contents overflow one "screen"? I'm talking about at design-time while using the ADT Layout Editor, not scrolling at run-time on a physical device (that works fine).

Changing the device type to a 10' tablet(layout editor top left 2nd option) made the screen big enough for me to fit everything in without having to scroll. Do your thing and then revert to normal size.