当我尝试从活动应用程序转换到自定义应用程序类时出现致命异常

Question

我需要从活动应用程序到我的自定义应用程序类进行转换 （需要它将存储库传递给 viewModelFactory 并在 viewModel 中使用它） 但在运行时我遇到了致命异常...我做错了什么？

这是我的自定义应用程序类：

class UserApplication : Application() {

  
    private val database by lazy { UsersRoomDatabase.getDatabase(this@UserApplication) }

   
    val repository by lazy { Repository(database.userDou()) }
}

尝试运行此：

val userApplication = requireActivity().application as UserApplication

例外：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.mytaskgame, PID: 7703
    java.lang.ClassCastException: android.app.Application cannot be cast to com.mytaskgame.application.UserApplication
        at com.mytaskgame.view.logIn.fragment.SignInFragment.onCreate(SignInFragment.kt:35)
        at androidx.fragment.app.Fragment.performCreate(Fragment.java:3009)
        at androidx.fragment.app.FragmentStateManager.create(FragmentStateManager.java:474)
        at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:257)
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1862)
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1786)
        at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1723)
        at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:510)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)