Question

我试图按照Google文档将广告投放到我的应用中，但始终遇到问题。

我的主要活动代码：

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

public class DongVatHoc extends AppCompatActivity {
private AdView mAdView;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.dong_vat_hoc_activity);

        // Sample AdMob app ID: ca-app-pub-3940256099942544~3347511713
        MobileAds.initialize(this, "ca-app-pub-3940256099942544~3347511713");

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

我的build.gradle（项目）：

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {

    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'


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

allprojects {
    repositories {
        google()
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

我的build.gradle（app）

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.nguyen.tubi.bich.testapp"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    //noinspection GradleCompatible
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.google.android.gms:play-services-ads:17.1.1'
}

还有我的dong_vat_hoc_activity.xml

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:background="@drawable/dong_vat_bg"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <GridView
        android:id="@+id/gridviewHinh"
        android:layout_width="match_parent"
        android:layout_height="477dp"
        android:paddingRight="4dp"
        android:gravity="center"
        android:numColumns="3">

    </GridView>

    <com.google.android.gms.ads.AdView
        xmlns:ads="http://schemas.android.com/apk/res-auto"
        android:id="@+id/adView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_alignParentBottom="true"
        ads:adSize="BANNER"
        ads:adUnitId="ca-app-pub-3940256099942544/6300978111">
    </com.google.android.gms.ads.AdView>

</LinearLayout>

以上所有内容我都遵循Google文档，但出现了问题：[Google文档]

'void com.google.android.gms.ads.AdView.loadAd(com.google.android.gms.ads.AdRequest)' on a null object reference

该行的问题：mAdView.loadAd（adRequest）;

所以请帮助我解决这个问题。

Answer 1

使用onAdFailedToLoad添加事件监听器

https://developers.google.com/admob/android/banner

Answer 2

通过在应用程序标记之间添加元数据来更新AndroidManifest.xml：

<application>
    <meta-data
        android:name="com.google.android.gms.ads.APPLICATION_ID"
        android:value="ca-app-pub-3940256099942544~3347511713"/>
</application>

希望对您有帮助

加载广告错误mAdView.loadAd（adRequest）;

2 个答案: