Is that possible to check was onCreate called because of orientation change?

Question

I need to act differently in onStart() method depending on how onCreate() was called in result of orientation change or not. Is that

Answer 1

Just check the bundle: when the activity is first started the bundle will be null. If there is an orientation change, it should be non-null.

From the android docs:

If the activity is being re-initialized after previously being shut down then this Bundle contains the data it most recently supplied in onSaveInstanceState(Bundle). Note: Otherwise it is null.

Edit: I don't think you have to supply a bundle in onSaveInstanceState for it to be non-null after an orientation change, but that would be trivial.