将 google 播放服务导入 android 项目失败

importing google play services to android project failed

我正在尝试将 AdMob 添加到我的应用程序中。我按照 here 列出的说明进行操作,但会导致以下导入失败并且无法解决 com.google.android.gms.ads 的错误:

import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;

这是我的根 gradle 文件:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.1.2'
        // ...
        classpath 'com.google.gms:google-services:3.0.0'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

这是我的应用程序 .gradle 文件:

    dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:support-v4:23.4.0'
    compile 'com.android.support:appcompat-v7:23.4.0'
    compile 'com.android.support:design:23.4.0'
    compile 'com.google.firebase:firebase-core:9.4.0'

}
apply plugin: 'com.google.gms.google-services'

我认为您忘记包含 admob 依赖项:

compile 'com.google.firebase:firebase-ads:9.4.0'

核心包只是此处所述的分析: https://firebase.google.com/docs/android/setup#available_libraries