how to solve the "type mismatch" and "unresolved reference" errors when converting MainActivity to a fragment in Kotlin?

Question

I'm trying to convert my MainActivity.kt into a Fragment, so the beggining of the code looks like this so far:

class MainActivity : Fragment() {
lateinit var mAdView : AdView    private lateinit var progressDialog: ProgressDialog
private var selectedtype = "Ultra fast"
private val binding by lazy {
    ActivityMainBinding.inflate(layoutInflater)
}



override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.main_activity, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    //setContentView(binding.root)
    progressDialog = ProgressDialog(this)
    progressDialog.setCancelable(false)
    progressDialog.setCanceledOnTouchOutside(false)
    inIt()
    MobileAds.initialize(this) {}
    mAdView = view.findViewById(R.id.adView)
    val adRequest = AdRequest.Builder().build()
    mAdView.loadAd(adRequest)
    
    getSupportActionBar()?.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM)
    getSupportActionBar()?.setCustomView(R.layout.actionbar_title)

}

I have this error:

Type mismatch: inferred type is MainActivity but Context! was expected

Here:

progressDialog = ProgressDialog(this)

and here:

MobileAds.initialize(this) {}

and this error:

Unresolved reference: getSupportActionBar

here:

getSupportActionBar()?.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM)
getSupportActionBar()?.setCustomView(R.layout.actionbar_title)

how can I solve those?

Enowneb · Answer 1 · 2023-02-22T09:33:12.233

An Activity is different from a Fragment. You cannot simply change AppCompatActivity into Fragment.

To get back the corresponding Activity from a Fragment, you have to use getActivity().

So for,

progressDialog = ProgressDialog(this)

You should have:

progressDialog = ProgressDialog(activity)

And for:

getSupportActionBar()?...

You should have:

(activity as AppCompatActivity).supportActionBar...

Note that your Activity should be an AppCompatActivity in order to use getSupportActionBar().

how to solve the "type mismatch" and "unresolved reference" errors when converting MainActivity to a fragment in Kotlin?

1 Answers1