我正在用一个简单的项目测试刀柄,我想要实现的是用刀柄生成我的 MainViewModel 的一个实例,这是我到目前为止所做的
主要 Activity
@AndroidEntryPoint
class MainActivity : AppCompatActivity() {
...
}
主要 fragment @AndroidEntryPoint
class MainFragment : Fragment(),MainAdapter.OnTragoClickListener {
private val viewModel by activityViewModels<MainViewModel>()
...
}
主视图模型class MainViewModel @ViewModelInject constructor(private val repo:Repo):ViewModel(){
...
}
RepoImplclass RepoImpl @Inject constructor(private val dataSource: DataSource): Repo {
...
}
数据源实现class DataSourceImpl @Inject constructor(private val tragosDao: TragosDao): DataSource{
...
}
现在,这是应用程序遵循的架构,这里是 Repo
和 DataSource
是我使用的简单接口(interface)。因此,在此之后,我生成了生成实例所需的所有内容
基础应用
@HiltAndroidApp
class BaseApplication: Application() {
}
应用模块@Module
@InstallIn(ApplicationComponent::class)
object AppModule {
@Singleton
@Provides
fun provideRoomInstance(
@ApplicationContext context: Context
) = Room.databaseBuilder(
context,
AppDatabase::class.java,
"tabla_tragos")
.build()
@Singleton
@Provides
fun provideTragosDao(db: AppDatabase) = db.tragoDao()
}
上面的模块提供了 tragoDao(),所以我可以在我的 DataSourceImpl
中访问它,因为我需要这个数据库的唯一实例,所以我使用 @Singleton
在其提供然后我只创建另一个模块,让 hilt 知道上面接口(interface)的实现
@Module
@InstallIn(ActivityRetainedComponent::class)
abstract class ActivityModule {
@Binds
abstract fun bindDataSource(dataSource:DataSourceImpl): DataSource
@Binds
abstract fun bindRepo(repo: RepoImpl): Repo
}
由于我需要 MainViewModel 的一个实例,我将这个模块的范围设置为 ActivityRetainedComponent
编译应用程序后出现此错误java.lang.RuntimeException: Cannot create an instance of class com.g.tragosapp.ui.viewmodel.MainViewModel
依赖项
apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'
apply plugin: 'dagger.hilt.android.plugin'
dependencies {
implementation fileTree(dir: "libs", include: ["*.jar"])
implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
implementation 'androidx.core:core-ktx:1.3.0'
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
//Navigation Components
implementation "androidx.navigation:navigation-fragment-ktx:2.3.0"
implementation "androidx.navigation:navigation-ui-ktx:2.3.0"
implementation 'androidx.legacy:legacy-support-v4:1.0.0'
//ViewModel y LiveData
implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
// KTX - Viewmodel Y Livedata
implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0'
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.3.0-alpha05"
implementation "androidx.fragment:fragment-ktx:1.2.5"
implementation "androidx.activity:activity-ktx:1.1.0"
//utils
implementation 'com.github.bumptech.glide:glide:4.11.0'
annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0'
//Corutinas
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.3"
//Retrofit
implementation 'com.squareup.retrofit2:retrofit:2.6.0'
implementation 'com.google.code.gson:gson:2.8.5'
implementation 'com.squareup.retrofit2:converter-gson:2.5.0'
implementation 'com.squareup.okhttp3:logging-interceptor:3.12.0'
implementation 'com.github.chrisbanes:PhotoView:2.3.0'
//Room
implementation 'androidx.room:room-ktx:2.2.5'
implementation "androidx.room:room-runtime:2.2.5"
kapt "androidx.room:room-compiler:2.2.5"
//Hilt
implementation "com.google.dagger:hilt-android:2.28-alpha"
kapt "com.google.dagger:hilt-android-compiler:2.28-alpha"
implementation 'androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha02'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}
我还添加了 implementation "androidx.fragment:fragment-ktx:1.2.5"
implementation "androidx.activity:activity-ktx:1.1.0"
implementation "androidx.core:core:1.3.1"
这没有任何区别
最佳答案
class RepoImpl
应该@Singleton class RepoImpl
DataSourceImpl
也是如此然后改
@InstallIn(ActivityRetainedComponent::class)
至@InstallIn(SingletonComponent::class)
(以前是ApplicationComponent)并确保拥有所有这些部门(在撰写本文时):
buildscript {
ext {
dagger_version = '2.41'
}
dependencies {
classpath "com.google.dagger:hilt-android-gradle-plugin:$dagger_version"
}
和apply plugin: 'dagger.hilt.android.plugin'
apply plugin: 'kotlin-kapt'
implementation "com.google.dagger:dagger:$dagger_version"
kapt "com.google.dagger:dagger-compiler:$dagger_version"
implementation "com.google.dagger:hilt-android:$dagger_version"
kapt "com.google.dagger:hilt-android-compiler:$dagger_version"
kaptTest "com.google.dagger:hilt-android-compiler:$dagger_version"
kaptAndroidTest "com.google.dagger:hilt-android-compiler:$dagger_version"
kapt 'androidx.hilt:hilt-compiler:1.0.0'
关于android - 无法使用 Hilt 创建 MainViewModel 的实例,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/63208779/