Android – DataBinding – How and when the Binding classes will be generated?

What is your layout name?

The above layout file was activity_main.xml so the generate class was ActivityMainBinding.

What this means is that the generated class name will depend on your layout’s name

activity_main.xml -> ActivityMainBinding.java

I think your activity name is “main_activity”, so the generated binding class name should be MainActivityBinding not ActivityMainBinding