UninitializedPropertyAccessException：lateinit属性pref尚未初始化

Question

我知道一个类似的问题已经在这里得到了回答。但那是由于黄油刀库的问题，但我的情况不同。在我的例子中，当我在基本活动中使用dagger injected属性时，它显示了由：kotlin.uninitializedPropertyAccessException引起的错误：lateinit属性pref尚未初始化

    abstract class BaseActivity : AppCompatActivity() {
    @Inject
    lateinit var pref: AppSharedPreferences
    @Inject
    lateinit var utils: Utils
    lateinit var mCurrentLanguage: String
    protected lateinit var progressBarUtils: ProgressBarUtils

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        progressBarUtils = ProgressBarUtils(this)
        mCurrentLanguage = "EN"
        pref.setSelectedLanguage(mCurrentLanguage)   
    }
    }

    class LoginActivity : BaseActivity() {
    private val TAG = this.javaClass.name
    lateinit var loginViewModel: LoginViewModel
    @Inject
    lateinit var viewModelFactory: LoginViewModelFactory


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)
        AndroidInjection.inject(this)
        loginViewModel = ViewModelProviders.of(this, viewModelFactory).get(
                LoginViewModel::class.java)
        loadData("abc", "xyz")
        observerOnLoginResult()
        observerOnLoginError()
    }


    private fun observerOnLoginError() {
        loginViewModel.loginError().observe(this, Observer<String> {
            progressBarUtils.cancelProgressDialog()
            if (it != null) {
                Toast.makeText(this, resources.getString(R.string.error_message) + it,
                        Toast.LENGTH_SHORT).show()
            }
        })
    }

    private fun observerOnLoginResult() {
        loginViewModel.loginResult().observe(this,
                Observer<LoginModel> {
                    progressBarUtils.cancelProgressDialog()
                    if (it != null) {
                        setData(it)
                    }
                })
    }

    private fun setData(loginData: LoginModel) {
        pref.setCurrentUserName(loginData.data.userName)
    }

    private fun loadData(email: String, password: String) {
        progressBarUtils.showProgressDialog()
        val builder = StringBuilder()
        var auth = Base64.encodeToString(("$email:$password").toByteArray(), Base64.NO_WRAP)
        builder.append("Basic ")
        builder.append(auth)
        loginViewModel.getLoginData(builder.toString())
    }

    override fun onDestroy() {
        loginViewModel.disposeElements()
        super.onDestroy()
    }

    @Module class AppModule(val app: Application) {

    @Provides
    @Singleton
    fun provideApplication(): Application = app


    @Provides
    @Singleton
    fun provideSharedPreferences(): AppSharedPreferences = AppSharedPreferences(app)


    @Provides
    @Singleton
    fun provideUtils(): Utils = Utils(app)
    }

    @Module abstract class BuildersModule {

    @PerActivity
    @ContributesAndroidInjector(modules = arrayOf(LoginModule::class))
    abstract fun contributeLoginActivity(): LoginActivity

    @PerActivity
    abstract fun contributeBaseActivityActivity(): BaseActivity
    }

AppComponent

    @Singleton @Component(
        modules = arrayOf(AndroidInjectionModule::class, AppModule::class, BuildersModule::class))

    interface AppComponent { 
      fun inject(app: LotusApp)            
    }

Answer 1

在初始化对象之前不能使用它。

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState) // prefs called in parents onCreate!
  setContentView(R.layout.activity_login)
  AndroidInjection.inject(this) // injection happens here

按顺序接电话。最简单的修复方法是在调用super.oncreate(...)之前移动androidinjection.inject(this)。