Я разрабатываю новостное приложение, и я внедрил живые данные с индикатором выполнения, но я получаю следующее исключение в своем коде
java.lang.IllegalStateException: pb must not be null
at yodgorbek.komilov.musobaqayangiliklari.ui.TopHeadlinesFragment$initViewModel$2.onChanged(TopHeadlinesFragment.kt:60)
at yodgorbek.komilov.musobaqayangiliklari.ui.TopHeadlinesFragment$initViewModel$2.onChanged(TopHeadlinesFragment.kt:22)
at androidx.lifecycle.LiveData.considerNotify(LiveData.java:131)
at androidx.lifecycle.LiveData.dispatchingValue(LiveData.java:144)
at androidx.lifecycle.LiveData$ObserverWrapper.activeStateChanged(LiveData.java:442)
at androidx.lifecycle.LiveData$LifecycleBoundObserver.onStateChanged(LiveData.java:394)
at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.java:361)
at androidx.lifecycle.LifecycleRegistry.forwardPass(LifecycleRegistry.java:300)
at androidx.lifecycle.LifecycleRegistry.sync(LifecycleRegistry.java:339)
at androidx.lifecycle.LifecycleRegistry.moveToState(LifecycleRegistry.java:145)
at androidx.lifecycle.LifecycleRegistry.handleLifecycleEvent(LifecycleRegistry.java:131)
at androidx.fragment.app.Fragment.performStart(Fragment.java:2637)
at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:915)
at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManagerImpl.java:1238)
at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1303)
at androidx.fragment.app.BackStackRecord.executeOps(BackStackRecord.java:439)
at androidx.fragment.app.FragmentManagerImpl.executeOps(FragmentManagerImpl.java:2079)
at androidx.fragment.app.FragmentManagerImpl.executeOpsTogether(FragmentManagerImpl.java:1869)
at androidx.fragment.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManagerImpl.java:1824)
at androidx.fragment.app.FragmentManagerImpl.execPendingActions(FragmentManagerImpl.java:1727)
at androidx.fragment.app.FragmentManagerImpl$2.run(FragmentManagerImpl.java:150)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:201)
at android.app.ActivityThread.main(ActivityThread.java:6820)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:922)
ниже моего класса TopHeadlinesFragment.kt
class TopHeadlinesFragment : Fragment() {
private var binding: FragmentTopHeadlinesBinding? = null
private val viewModel by viewModel<MainViewModel>()
private lateinit var topHeadlinesAdapter: TopHeadlinesAdapter
// private val newsRepository: NewsRepository by inject()
private var article:List<Article>? = null
//3
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(
R.layout.fragment_top_headlines
, container, false
)
val recyclerView = view.findViewById(R.id.recyclerView) as RecyclerView
val pb = view.findViewById(R.id.pb) as ProgressBar
topHeadlinesAdapter = TopHeadlinesAdapter(recyclerView.context, article)
recyclerView.layoutManager = LinearLayoutManager(context)
recyclerView.adapter = topHeadlinesAdapter
initViewModel()
binding?.lifecycleOwner
return binding?.root
}
private fun initViewModel() {
viewModel?.sportList?.observe(this, Observer { newList ->
topHeadlinesAdapter.updateData(newList)
})
viewModel?.showLoading?.observe(this, Observer { showLoading ->
pb.visibility = if (showLoading) View.VISIBLE else View.GONE
})
viewModel?.showError?.observe(this, Observer { showError ->
(showError)
})
viewModel?.loadNews()
}
}
ниже фрагмент_top_headlines.xml
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ProgressBar
android:id="@+id/pb"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
I have followed all stackoverflow suggestion it did not solve my problem. what I want to know where exactly I am making mistake what I have to in order avoid an exception.
что я пробовал
1. Недействительный перезапуск кеша 2. Очистить и перестроить проект 3. Я проверил, что индикатор выполнения уже инициализирован. 4. Я также попробовал эту ссылку stackoverflow используя Kotlin 5. Я пробовал индикатор выполнения, объявленный как глобальная переменная, но это не сработало
ниже моего MainViewModel.kt
@Suppress("UNCHECKED_CAST")
class MainViewModel(val newsRepository: NewsRepository) : ViewModel(), CoroutineScope {
// Coroutine's background job
val job = Job()
// Define default thread for Coroutine as Main and add job
override val coroutineContext: CoroutineContext = Dispatchers.Main + job
val showLoading = MutableLiveData<Boolean>()
val sportList = MutableLiveData<List<Article>>()
val showError = SingleLiveEvent<String>()
fun loadNews() {
// Show progressBar during the operation on the MAIN (default) thread
showLoading.value = true
// launch the Coroutine
launch {
// Switching from MAIN to IO thread for API operation
// Update our data list with the new one from API
val result = withContext(Dispatchers.IO) {
newsRepository?.getNewsList()
}
// Hide progressBar once the operation is done on the MAIN (default) thread
showLoading.value = false
when (result) {
is UseCaseResult.Success<*> -> {
sportList.value = result.data as List<Article>
}
is Error -> showError.value = result.message
}
}
}
override fun onCleared() {
super.onCleared()
// Clear our job when the linked activity is destroyed to avoid memory leaks
job.cancel()
}
}
Я также пробовал ниже предоставленные ответы, но это не решило проблему
