android kotlin data-binding kapt missing

Question

I'm trying to move to kotlin in android, and tried data-binding like this:

        mBinding = DataBindingUtil.setContentView(this, R.layout.activity_authentication)
        viewModel = ViewModelProvider.AndroidViewModelFactory.getInstance(application)
            .create<AuthViewModel>(AuthViewModel::class.java)
//mBinding.auth.invoke(viewModel)
        mBinding.auth.invoke(viewModel)
        mBinding.setLifecycleOwner(this)

It gave me can't be invoked as function, so auto-generated this:

public void invoke(@NotNull AuthViewModel viewModel) {

    }
...

But it keeps saying it's mutable, can be changed by now.

How should I resolve this?

And gradle file says, I should use kapt, I don't know what is that

Answer 1

try initilalizing binding before oncreate by

private lateinit var binding : /*your layout name in camelcase*/Binding /*like ActivityMainBinding*/
private lateinit var viewmodel : AuthViewModel

then in onCreate

binding = ActivityMainBinding.inflate(layoutInflator)
viewmodel = ViewModelProvider(this,factory).get(AuthViewModel::class.java)

also make sure you added
buildFeatures { dataBinding true } in app gradle file`inside android