错误[Dagger / MissingBinding]如果没有@Provides注释的方法，则无法提供androidx.lifecycle.ViewModelProvider.Factory [英] Error [Dagger/MissingBinding] androidx.lifecycle.ViewModelProvider.Factory cannot be provided without an @Provides-annotated method
问题描述
使用匕首2.2实现MultiBinding时遇到问题。我在MVVM体系结构中使用了匕首。我注入了 ViewModelProvideFactory 构造函数并绑定了模块的依赖关系。
I am facing an issue while implementing MultiBinding using dagger 2.2. I am using dagger with MVVM architecture. I have injected the ViewModelProvideFactory constructor and binds the dependency from module.
我遵循了YouTube上Mitch的教程
I have followed the tutorial of Mitch from youtube
https://www.youtube.com/watch?v=DToD1W9WdsE&list=PLgCYzUzKIBE8AOAspC3DHoBNZIBHbIOsC&index=13
我在这些链接上搜索了解决方案，但仍然面临相同的问题。
I have searched on these links for the solutions but still facing the same issue.
Dagger2：如果没有@Provides注释的方法，则无法提供ViewModel
https://github.com/google/dagger/issues/1478
代码段
ViewModelKey
@MapKey
@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface ViewModelKey {
Class<? extends ViewModel> value();
}
ViewModelFactoryModule
/**
* ViewModelFactoryModule responsible for providing [ViewModelProviderFactory]
*
* Annotated with Module to tell dagger it is a module to provide [ViewModelProviderFactory]
*
* Annotated with bind annotation to efficiently provide dependencies similar to provides annotation
*/
@Module
abstract class ViewModelFactoryModule {
@Binds
abstract fun bindViewModelFactory(viewModelFactory: ViewModelProviderFactory) : ViewModelProvider.Factory
}
ViewModelProviderFactory
@Singleton
class ViewModelProviderFactory @Inject
constructor(private val creators: Map<Class<out ViewModel>, @JvmSuppressWildcards Provider<ViewModel>>) :
ViewModelProvider.Factory {
override fun <T : ViewModel> create(modelClass: Class<T>): T {
var creator: Provider<out ViewModel>? = creators[modelClass]
if (creator == null) { // if the viewmodel has not been created
// loop through the allowable keys (aka allowed classes with the @ViewModelKey)
for ((key, value) in creators) {
// if it's allowed, set the Provider<ViewModel>
if (modelClass.isAssignableFrom(key)) {
creator = value
break
}
}
}
// if this is not one of the allowed keys, throw exception
if (creator == null) {
throw IllegalArgumentException("unknown model class $modelClass")
}
// return the Provider
try {
return creator.get() as T
} catch (e: Exception) {
throw RuntimeException(e)
}
}
companion object {
private val TAG = "ViewModelProviderFactor"
}
}
StackTrace
> Task :app:kaptDebugKotlin FAILED
e: /Users/fazal/Documents/fazal/demo/AdvanceDagger2/app/build/tmp/kapt3/stubs/debug/com/example/advancedagger2/di/AppComponent.java:22: error: [Dagger/MissingBinding] java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> cannot be provided without an @Provides-annotated method.
public abstract interface AppComponent extends dagger.android.AndroidInjector<com.example.advancedagger2.BaseApplication> {
^
java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> is injected at
com.example.advancedagger2.viewmodel.ViewModelProviderFactory(viewModelsMap)
com.example.advancedagger2.viewmodel.ViewModelProviderFactory is injected at
com.example.advancedagger2.ui.AuthActivity.viewModelFactory
com.example.advancedagger2.ui.AuthActivity is injected at
dagger.android.AndroidInjector.inject(T) [com.example.advancedagger2.di.AppComponent → com.example.advancedagger2.di.ActivityBuilderModule_ContributeAuthActivity.AuthActivitySubcomponent]
我已经降级了Kotlin版本，但仍然面临相同的问题。告诉我，我做错了吗？
I have downgraded the Kotlin version but still facing the same issue. Tell me what, I am doing wrong?
编辑1
我还通过AuthViewModel提供ViewModel。活动范围。当活动破坏了它的组件并且依赖关系也被破坏了。
I am also providing ViewModel through AuthViewModel which is on the scope of activity. When activity destroys its component and dependencies also destroy.
AuthViewModelModule
@Module
abstract class AuthViewModelModule {
/**
* Binds the auth view model dependency with [ViewModelKey] to group similar [ViewModel]
*
* Under the hood it is providing [com.example.advancedagger2.viewmodel.AuthViewModel]
*/
@Binds
@IntoMap
@ViewModelKey(AuthViewModel::class)
abstract fun bindAuthViewModel(authViewModel: AuthViewModel) : ViewModel
}
ActivityBuilderModule
/**
* This Class {@linkplain ActivityBuilderModule} is responsible for for android injection
* for the activity with in the application to avoid the seprate injection in each activity
*
* {@linkplain dagger.android.AndroidInjection#inject(Activity)}
*
* {@link com.example.advancedagger2.viewmodel.AuthViewModel} can be access from Auth Activity
* only so it is the concept of sub-modules
*
*/
@Module
public abstract class ActivityBuilderModule {
@ContributesAndroidInjector(
modules = AuthViewModelModule.class
)
abstract AuthActivity contributeAuthActivity();
}
推荐答案
根据我的评论解决了这个问题
According to the comment I have solved the issue
您的工厂可能不应该是@Singleton。它是轻量级的，
不携带任何状态，并且您的视图模型可能绑定在
活动相关范围内，并且无论如何在@Singleton中都无法使用
Your factory probably shouldn't be @Singleton. It's lightweight, doesn't carry any state, and your viewmodels probably get bound in an activity related scope and aren't available in @Singleton anyways
我用 @Singleton 注释了工厂，该活动在活动范围中不可用。我刚刚删除了 @Singleton 批注。一切都按预期进行
I have annotated factory with @Singleton which cannot be available in activity scope. I have just removed the @Singleton annotation. Everything is working as expected
这篇关于错误[Dagger / MissingBinding]如果没有@Provides注释的方法，则无法提供androidx.lifecycle.ViewModelProvider.Factory的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
