New to Android Studio 3x, first noticed it gave me two views in design mode. 2x has only the left one, what's this right one for and what's good about it? Can I get rid of it?
2) After placing a ListView on the left view and gave it a name, it supposed show like this in older versions. It doesn't. So can I select this ListView later?
Just found answer to 2nd question, I noticed a red ! at the upper corner of design mode, clicked on it, "Failed to load AppCompat...". Found the 2nd answer on this thread solves my problem, now ListView appear at left hand side.
After that, it also addresses my 1st question as below. Still don't know how to get rid of the right one.