What is the difference between `bind`, `inflate` and `setContentView` in `DataBindingUtil`

Question

I have seen DataBindingUtil used with all three methods, and it is not clear from the documentation (https://developer.android.com/reference/android/databinding/DataBindingUtil) what the difference is between the three.

Answer 1

bind takes an already inflated view hierarchy and returns a ViewDataBinding for it.

inflate takes a layout resource ID, inflates a view hierarchy from it and returns a ViewDataBinding for it. It's essentially equal to

val layoutInflater = LayoutInflater.from(context)
val view = layoutInflater.inflate(R.layout.some_layout, ...)
val binding = DataBindingUtil.bind<SomeLayoutBinding>(view)

setContentView takes a layout resource ID, inflates a view hierarchy from it, sets it as an activity content and returns a ViewDataBinding for the inflated view hierarchy. It's essentially equal to

setContentView(R.layout.some_layout)
val view = findViewById<View>(android.R.id.content)
val binding = DataBindingUtil.bind<SomeLayoutBinding>(view)