我想在我的 Android 应用程序中实现 Hilt，但应用程序不断崩溃

Question

我正在使用 kotlin 编写一个 Android 应用程序，并且正在尝试实现 Firebase 身份验证。我正在使用 Hilt，但是我不断收到不知道如何修复的错误。应用程序不断崩溃，从 logcat 中我知道错误与 ViewModel 有关。

FATAL EXCEPTION: main
Process: com.example.mp_draft10, PID: 3832
java.lang.RuntimeException: Cannot create an instance of class com.example.mp_draft10.auth.SignUpViewModel
    at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.kt:201)
    at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:320)
    at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:302)
    at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:276)
    at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:128)
    at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:173)
    at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:184)
    at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:150)
    at androidx.lifecycle.viewmodel.compose.ViewModelKt.get(ViewModel.kt:215)
    at androidx.lifecycle.viewmodel.compose.ViewModelKt.viewModel(ViewModel.kt:156)
    at com.example.mp_draft10.auth.SignUpScreenKt.SignUpScreen(SignUpScreen.kt:103)
    at com.example.mp_draft10.ComposableSingletons$MainActivityKt$lambda-5$1.invoke(MainActivity.kt:94)
    at com.example.mp_draft10.ComposableSingletons$MainActivityKt$lambda-5$1.invoke(MainActivity.kt:93)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:139)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
    at androidx.navigation.compose.NavHostKt$NavHost$14$1.invoke(NavHost.kt:308)
    at androidx.navigation.compose.NavHostKt$NavHost$14$1.invoke(NavHost.kt:306)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
    at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:248)
    at androidx.compose.runtime.saveable.SaveableStateHolderImpl.SaveableStateProvider(SaveableStateHolder.kt:84)
    at androidx.navigation.compose.NavBackStackEntryProviderKt.SaveableStateProvider(NavBackStackEntryProvider.kt:65)
    at androidx.navigation.compose.NavBackStackEntryProviderKt.access$SaveableStateProvider(NavBackStackEntryProvider.kt:1)
    at androidx.navigation.compose.NavBackStackEntryProviderKt$LocalOwnersProvider$1.invoke(NavBackStackEntryProvider.kt:52)
    at androidx.navigation.compose.NavBackStackEntryProviderKt$LocalOwnersProvider$1.invoke(NavBackStackEntryProvider.kt:51)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
    at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
    at androidx.navigation.compose.NavBackStackEntryProviderKt.LocalOwnersProvider(NavBackStackEntryProvider.kt:47)
    at androidx.navigation.compose.NavHostKt$NavHost$14.invoke(NavHost.kt:306)
    at androidx.navigation.compose.NavHostKt$NavHost$14.invoke(NavHost.kt:295)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:139)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
    at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1$5.invoke(AnimatedContent.kt:755)
    at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1$5.invoke(AnimatedContent.kt:744)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:118)
    at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
    at androidx.compose.animation.AnimatedVisibilityKt.AnimatedEnterExitImpl(AnimatedVisibility.kt:818)
    at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1.invoke(AnimatedContent.kt:726)
    at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1.invoke(AnimatedContent.kt:709)

这是错误似乎与之相关的类

import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import com.example.mp_draft10.auth.util.Resource
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.flow.receiveAsFlow
import kotlinx.coroutines.launch
import javax.inject.Inject
class SignUpViewModel @Inject constructor(
    private val repository: AuthRepository
): ViewModel() {

    val _signUpState = Channel<SignInState>()
    val signUpState = _signUpState.receiveAsFlow()

    fun registerUser(email: String, password: String) = viewModelScope.launch {
        repository.loginUser(email,password).collect{result ->
            when(result){
                is Resource.Success ->{
                    _signUpState.send(SignInState(isSuccess = "Sign in success"))
                }
                is Resource.Loading ->{
                    _signUpState.send(SignInState(isLoading = true))
                }
                is Resource.Error ->{
                    _signUpState.send(SignInState(isError = result.message))
                }
            }
        }
    }
}

Answer 1

如 https://developer.android.com/training/dependency-injection/hilt-android#android-classes 中所述，如果您使用

@HiltViewModel

对其进行注释，Hilt 可以为您提供视图模型。您的代码中似乎缺少该注释，这可能是您遇到错误的原因。

Answer 2

使用

@HiltViewModel

注释来注释您的视图模型，然后它应该可以工作