23.4 Creating View IDs
When the layout is complete it will consist of a Button and an EditText view. Before these views can be referenced within the methods of the ConstraintSet class, they must be assigned unique view IDs. The first step in this process is to create a new resource file containing these ID values.
Right click on the app -> res -> values folder, select the New -> Values resource file menu option and name the new resource file id.xml. With the resource file created, edit it so that it reads as follows:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<item name="myButton" type="id" />
<item name="myEditText" type="id" />
</resources>
At this point in the tutorial, only the Button has been created, so edit the createLayout() method to assign the corresponding ID to the object:
private void configureLayout...