无法解析:firebase common

尝试添加firebase auth时出现此错误

无法解析:firebase common

build.gradle公司

apply plugin: 'com.android.application'

android {
compileSdkVersion 27
buildToolsVersion '27.0.3'
defaultConfig {
...
}

dependencies {
implementation 'com.google.firebase:firebase-core:15.0.2'
implementation 'com.google.firebase:firebase-messaging:15.0.2'
implementation 'com.google.firebase:firebase-crash:15.0.2'
implementation 'com.google.firebase:firebase-appindexing:15.0.1'
implementation 'com.google.firebase:firebase-invites:15.0.1'
implementation fileTree(include: ['*.jar'], dir: 'libs')
androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
implementation 'com.google.firebase:firebase-firestore:16.0.0'
implementation 'com.firebaseui:firebase-ui-auth:4.0.0'
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support.constraint:constraint-layout:1.1.0'
implementation 'com.android.support:design:27.1.1'
implementation 'com.android.support:support-v4:27.1.1'
implementation 'com.android.support:support-vector-drawable:27.1.1'
implementation 'com.android.support:recyclerview-v7:27.1.1'
implementation 'com.android.support:cardview-v7:27.1.1'
implementation 'com.google.code.gson:gson:2.8.2'
testImplementation 'junit:junit:4.12'
 }
 // Add to the bottom of the file - this is for Google Firebase
 apply plugin: 'com.google.gms.google-services'

直到我添加了“实现”的用户界面,所有的东西都会起作用。

谢谢你的帮助!