Kotlin get type of generic class without instance

2019-06-28 08:07发布

问题:

Hey want go get Type of T , but I can not get it from instance, I have to get it from class parameter, how to do it?

abstract class ViewModelFragment<T : ViewModel>{
    protected lateinit var mViewModel: T

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
       mViewModel = ViewModelProviders
                    .of(scope)
                    .get(getGenericTClass())
    // .get(mViewModel.javaClass) // not working either

   }

   inline fun<reified R> getGenericTClass() = R::class.java

}

Right now compiler complains

Cannot use 'T' as refined class type. Use Class instead.

I've tried to use solution of: https://stackoverflow.com/a/34463352/2163045 but not working for me

回答1:

I have the same issue and code below helped me:

  val persistentClass = (javaClass.genericSuperclass as ParameterizedType).actualTypeArguments[0] as Class<T>
    mViewModel = ViewModelProviders.of(this, viewModelsFactory).get(persistentClass)