UninitializedPropertyAccessException:lateinit属性尚未初始化 [英] UninitializedPropertyAccessException: lateinit property has not been initialized

问题描述

我有一个类，我将其注入到ViewModel + ViewModel工厂中，当在活动中的onCreate方法中初始化视图模型时，它说正在传递的值未初始化.

I have a class which i inject into a ViewModel + ViewModel factory, when initialise the view model in the onCreate method in activity, its says the value being passed through is not initialised.

下面是我的代码

我对Kotlin还是很陌生，所以尝试了调试，但在此问题上陷入了困境.

I am quite new to Kotlin so have tried debugging but am stuck on this issue.

这是MainActivity代码:

class MainActivity: AppCompatActivity(), RepoSelectedListener {


    @Inject
    lateinit var viewModel: MainActivityListViewModel

    lateinit var lifecycleOwner: LifecycleOwner
    lateinit var repoSelectedListener: RepoSelectedListener

    @Inject
    lateinit var repository: RepoRepository


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        viewModel = ViewModelProviders.of(this, ViewModelFactory(repository)).get(MainActivityListViewModel::class.java)

        repoRecyclerView.apply {
            layoutManager = LinearLayoutManager(context)
            adapter = RepoListAdapter(viewModel, lifecycleOwner, repoSelectedListener)
        }


**My ViewModel:**



   class MainActivityListViewModel @Inject constructor(val 
    repoRepository: RepoRepository): BaseViewModel() {

    //private lateinit var repoRepository: RepoRepository
    private var disposable: CompositeDisposable? = null

    private val repos = MutableLiveData<List<Repo>>()
    private val repoLoadError = MutableLiveData<Boolean>()
    private val loading = MutableLiveData<Boolean>()


     init {
        disposable = CompositeDisposable()
        fetchRepos()
      }

     fun getRepos(): LiveData<List<Repo>> {
        return repos
     }
    }

我的ViewModelFactory:

   class ViewModelFactory @Inject constructor(private val 
   repoRepository: RepoRepository): ViewModelProvider.Factory{


    override fun <T : ViewModel?> create(modelClass: Class<T>): T {
        if 
   (modelClass.isAssignableFrom(MainActivityListViewModel::class.java)) 
   {
            @Suppress("UNCHECKED_CAST")
            return MainActivityListViewModel(this.repoRepository) as T
        }
        throw IllegalArgumentException("Unknown ViewModel class")

    }


   }

我的班级回购:

  class RepoRepository @Inject constructor(private val githubRepos: 
    GithubRepos){


    private lateinit var repoService: GithubRepos


    fun getRepositories(): Single<List<Repo>> {
        return repoService.getRepos()
    }

    fun getSingleRepo(owner: String, name: String): Single<Repo> {
        return repoService.getSingleRepo(owner, name)
    }
   }

这是我收到的错误:

   Unable to start activity ComponentInfo{com.carllewis14.repos/com.carllewis14.repos.ui.MainActivity}: kotlin.UninitializedPropertyAccessException: lateinit property 
  repository has not been initialized

推荐答案

在这里查看我的答案(也许有帮助)

have a look at my answer here (maybe it helps ) Nullable var with `?` vs. lateinit var

本质上，您永远不会初始化repository: RepoRepository.

Essentially, you are never initializing your repository: RepoRepository.

根据您编写的代码，您也无需在活动中使用存储库实例，而只需在ViewModel(具有注入功能)的构造函数中创建

From the code you have written, you won't need an instance of your repository in your activity as well, it should just be created in the constructor of your ViewModel (which has injection)

您还将在private lateinit var repoService: GithubRepos中遇到类似的问题；如果它在对象的构造函数中，则无需再次声明.

You are also going to have a similar issue with private lateinit var repoService: GithubRepos; if it's in the constructor of your object, you don't have to declare it again.

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