Why does platform type doesn't match nonnull object

Question

I am new in learning kotlin and trying to start a android application project with it.

After I created a project, I got stuck in the first line of code I wrote..

So this is my code and error.

I made MainFragment class extend Fragment and passed it's instance to beginTransaction().add() method.

I know that Fragment! is a platform type and it is type of Java class instantiated.

But I think there is no reason Fragment type doesn't math Fragment!.

How do I solve this problem?

+) I also tried MainFragment() as Fragment as FragmentTransaction won't Compile in Kotlin Android Project says, but it didn't work.

+) Also tried newInstance() in companion object

did you imported right fragment type v4? like import android.support.v4.app.Fragment — yogesh lokhande, Feb 02 '18 at 05:12
@YoLo Nope, I didn't, Kotlin was not the problem.. Thank you man!!!! — Hyun I Kim, Feb 02 '18 at 05:13

score 1 · Accepted Answer · answered Feb 02 '18 at 11:38

1

In your fragment MainFragment,
use import android.support.v4.app.Fragment in place of import android.app.Fragment. and then it should work.

answered Feb 02 '18 at 11:38

niketshah09

1 Answers1