将 MutableMap 更改为 Map 时 ViewModelFactory 出现 Dagger2 错误

Question

我在尝试使用 dagger2 时遇到问题这是我的 ViewModelFactory：

class ViewModelFactory @Inject constructor(
private val viewModels: MutableMap<Class<out ViewModel>, Provider<ViewModel>>) : ViewModelProvider.Factory {

override fun <T : ViewModel?> create(modelClass: Class<T>): T {
    val creator = viewModels[modelClass]
        ?: viewModels.asIterable().firstOrNull {
            modelClass.isAssignableFrom(it.key)
        }?.value ?: throw IllegalArgumentException("$UNKNOWN_MODEL_CLASS $modelClass")
    return try {
        @Suppress("UNCHECKED_CAST")
        creator.get() as T
    } catch (e: Exception) {
        throw RuntimeException(e)
    }
}

}

当我将 viewModels 更改为 Map 时出现以下错误：

public abstract interface AppComponent {
            ^
  java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,? extends javax.inject.Provider<androidx.lifecycle.ViewModel>> is injected at
      com.example.baseproject.utils.ViewModelFactory(viewModels)
  com.example.baseproject.utils.ViewModelFactory is injected at
      com.example.baseproject.di.ViewModelBuilder.bindViewModelFactory(viewModelFactory)
  androidx.lifecycle.ViewModelProvider.Factory is injected at
      com.example.baseproject.MainActivity.viewModelFactory
  com.example.baseproject.MainActivity is injected at
      dagger.android.AndroidInjector.inject(T) [com.example.baseproject.di.AppComponent → com.example.baseproject.di.ActivityModules_ContributeMainActivity.MainActivitySubcomponent]

请帮帮我，我不知道为什么会这样

Answer 1

您缺少 @JvmSuppressWildcards。你想得到一个 Provider<ViewModel>，而不是 Provider<? extends ViewModel>，但 Kotlin 会为你生成一个没有注释的 Provider<? extends ViewModel>。

private val viewModels: Map<Class<out ViewModel>, @JvmSuppressWildcards Provider<ViewModel>>) : ViewModelProvider.Factory {

将 MutableMap 更改为 Map 时 ViewModelFactory 出现 Dagger2 错误

Dagger2 Error in ViewModelFactory when change MutableMap to Map

android

kotlin

dagger

dagger-2

android-viewmodel