我收到此错误 "com.example.viewmodelfactory.MainModelFactory cannot be cast to androidx.lifecycle.ViewModel "

Question

谁能告诉我如何从 MainActivity 传递 ViewModelFactory 中的默认值。我遇到错误 com.example.viewmodelfactory.MainModelFactory cannot be cast to androidx.lifecycle.ViewModel

class MainModelFactory (val counter: Int): ViewModelProvider.Factory {

    override fun <T : ViewModel?> create(modelClass: Class<T>): T {
        return MainModelFactory(counter) as T

}

这是我的 ViewModelClass

 class MainViewModel(val intiallizeCount: Int) :ViewModel () {   
 var count : Int = intiallizeCount

     fun Increment()
     {
         count++
     }
 }

我在 MainActivity 中传递默认计数值

mainViewModel=ViewModelProvider(this, MainModelFactory(10)).get(MainViewModel:: class.java)

Answer 1

ViewModelProvider.Factory returns 作为 ViewModel 对象，即

return MainViewModel(counter) as T

我收到此错误 "com.example.viewmodelfactory.MainModelFactory cannot be cast to androidx.lifecycle.ViewModel "

I'm getting this error "com.example.viewmodelfactory.MainModelFactory cannot be cast to androidx.lifecycle.ViewModel "

kotlin

viewmodelfactory