Kotlin中的ViewModel:未解决的参考 [英] ViewModel in Kotlin: Unresolved Reference

问题描述

我正在尝试在100％Kotlin应用中实现ViewModel.我能找到的每篇文档都说我想用它来获取ViewModel实例:

I am trying to implement ViewModel in a 100% Kotlin app. Every piece of documentation I can find says I want to use this to get the ViewModel instance:

ViewModelProviders.of(this).get(CustomViewModel::class.java)

根据文档，我应该可以使用以下命令导入该文件:

According to the docs, I should be able to import this with:

import android.arch.lifecycle.ViewModelProviders

此导入尚未解决.我在构建文件中使用了以下内容:

This import is unresolved though. I am using the following in my build file:

def androidArchVersion = '1.1.1'
implementation "android.arch.lifecycle:viewmodel:$androidArchVersion"
implementation "android.arch.lifecycle:livedata:$androidArchVersion"
annotationProcessor "android.arch.lifecycler:compiler:$androidArchVersion"
testImplementation "android.arch.core:core-testing:$androidArchVersion"

为什么我不能访问ViewModelProviders?

推荐答案

包括以下内容作为依赖项:

Include the following as a dependency:

implementation "android.arch.lifecycle:extensions:1.1.1"

此依赖关系同时适用于ViewModel和LiveData，因此不需要您为相同的视图分别提供依赖关系；即您所指示的前两个依赖项可以由上述生命周期扩展依赖项代替.

This dependency is for both ViewModel and LiveData and thus would not require you to give separate dependencies for the same either; i.e. the first two dependencies indicated by you can be replaced by the aforementioned lifecycle extensions dependency.

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