实现androidx生命周期依赖失败

Question

我正在学习使用Android Studio，当我想在Gradle中实现生命周期依赖时，同步后出现错误消息。我不明白为什么，但我按照Android Studio文档中的指示做了所有事情。你知道我错在哪里吗?输入图片描述

val lifecycle_version = "2.5.1"
val arch_version = "2.1.0"
// ViewModel
implementation("androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version")
// ViewModel utilities for Compose
implementation("androidx.lifecycle:lifecycle-viewmodel-compose:$lifecycle_version")
// LiveData
implementation("androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version")
// Lifecycles only (without ViewModel or LiveData)
implementation("androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version")
// Saved state module for ViewModel
implementation("androidx.lifecycle:lifecycle-viewmodel-savedstate:$lifecycle_version")
// Annotation processor
kapt("androidx.lifecycle:lifecycle-compiler:$lifecycle_version")
// alternately - if using Java8, use the following instead of lifecycle-compiler
implementation("androidx.lifecycle:lifecycle-common-java8:$lifecycle_version")
// optional - helpers for implementing LifecycleOwner in a Service
implementation("androidx.lifecycle:lifecycle-service:$lifecycle_version")
// optional - ProcessLifecycleOwner provides a lifecycle for the whole application process
implementation("androidx.lifecycle:lifecycle-process:$lifecycle_version")
// optional - ReactiveStreams support for LiveData
implementation("androidx.lifecycle:lifecycle-reactivestreams-ktx:$lifecycle_version")
// optional - Test helpers for LiveData
testImplementation("androidx.arch.core:core-testing:$arch_version")
// optional - Test helpers for Lifecycle runtime
testImplementation ("androidx.lifecycle:lifecycle-runtime-testing:$lifecycle_version")

Answer 1

替换val与def．在我的情况下，它正在工作。