The ability to see the design view and layout XML at the same time, side by side, was one of our most requested features for the Android Designer. With Split View, new in the Visual Studio 2017 version 15.8 release, you can switch back & forth freely between both modes of working. Edit the layout XML to see the changes immediately previewed in the designer or make changes in the designer and see the XML update. (Note: Split View is currently just available on Windows, not yet on Visual Studio for Mac.)