无法解析“：app @ debug / compileClasspath”的依赖项：无法解析com.google.firebase：firebase-messaging：17.1.0
当前，我正在开发一个android聊天应用程序。我想在我的应用程序中添加FCM。但是我总是收到这个gradle错误。根据我的阅读，firebase auth，数据库和消息传递依赖项版本应该匹配。我已经尝试了每个版本，但仍然会发生相同的错误。
Currently, I am working on an android chat application. I want to add FCM in my app. But I am always getting this gradle error. From what I have read, the firebase auth, database and messaging dependency version should match. I have tried every version, still, the same error occurs.
要解决此问题，请更改以下代码行：
To solve this, please change the following line of code:
com.google.firebase:firebase-auth:16.0.1
至
com.google.firebase:firebase-auth:16.0.2
并添加：
com.google.firebase:firebase-core:16.0.1
现在强制执行。也不要忘记添加：
Which is mandatory now. Don't also forget to add:
apply plugin: 'com.google.gms.google-services'
在文件末尾和以下代码行：
At the end of your file and the following line of code:
classpath 'com.google.gms:google-services:4.0.2'
放入您的 build.gradle 文件（项目）。
Into your build.gradle file (Project).
PS。如果您使用的是Firebase-UI身份验证，请同时添加以下代码行：
PS. If you are using Firebase-UI auth, add also this line of code:
com.firebaseui:firebase-ui-auth:4.0.1