android - 无法解析符号 'MobileAds'

Question

好的，所以我正在开发一个 Android 应用程序，我试图在其中放置广告，但每当我尝试编译它时，我都会收到错误“无法解析符号‘MobileAds’”。

这是我所拥有的:

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

public class MainActivity extends ListActivity {
private ArrayList<Sound> mSounds = null;
private SoundAdapter mAdapter = null;
static MediaPlayer mMediaPlayer = null;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    MobileAds.initialize(getApplicationContext(), "ca-app-pub-Removed");

    AdView mAdView = (AdView) findViewById(R.id.adView);
    AdRequest adRequest = new AdRequest.Builder().build();
    mAdView.loadAd(adRequest);
}

我的 XML:

xmlns:ads="http://schemas.android.com/apk/res-auto"  
<com.google.android.gms.ads.AdView
    android:id="@+id/adView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_alignParentBottom="true"
    ads:adSize="BANNER"
    ads:adUnitId="@string/banner_ad_unit_id">
</com.google.android.gms.ads.AdView>

和

<string name="banner_ad_unit_id">ca-app-pub-(removed)</string>

项目 Gradle

 dependencies {
    classpath 'com.android.tools.build:gradle:2.2.0'
    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
}

应用 Gradle

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:24.2.1'
compile 'com.google.firebase:firebase-core:9.6.1'
compile 'com.google.firebase:firebase-ads:9.6.0'
testCompile 'junit:junit:4.12'


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

为什么我会收到此错误消息？在此方面的任何帮助表示赞赏。谢谢!

Answer 1

遇到这个问题的人:

确保你有

import com.google.android.gms.ads.MobileAds;

在你的 MainActivity.java 中