ConstraintLayout: how to have a view be half the screen width and centered?

Question

TL;DR
The view width must be exactly half of the screen, and be centered. Using ConstraintLayout.

Note that the view does not have

Answer 1

With ConstraintLayout, you can center a view in the screen like this:

Update your gradle to the last version of ConstraintLayout:

dependencies {
...
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
}