我刚刚开始编写一个 Android 应用程序,想要使用 ViewModel。我查看了官方文档并添加了来自Lifecycle的所有依赖项,但是当我尝试像这样实例化 ViewModelMyViewModel by viewModels()
时,出现错误“未解决的引用:viewModels()”。
以下是依赖项:
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.core:core-ktx:1.2.0'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
testImplementation 'junit:junit:4.13'
androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
def lifecycle_version = "2.2.0"
def arch_version = "2.1.0"
implementation "android.arch.lifecycle:extensions:1.1.1"
kapt "android.arch.lifecycle:compiler:1.1.1"
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-viewmodel-savedstate:$lifecycle_version"
kapt "androidx.lifecycle:lifecycle-compiler:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-service:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-process:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-reactivestreams-ktx:$lifecycle_version"
testImplementation "androidx.arch.core:core-testing:$arch_version"
}