Question

尝试在ContraintLayout上使用横幅广告时遇到此错误。我在stackoverflow上查找了其他答案，但它们没有解决我的问题。

此代码在不同的布局上对我有用。布局是问题所在，只是不确定是什么原因造成的。

Java：

    AdRequest adRequestBanner = new AdRequest.Builder().build();
    MobileAds.initialize(this, getString(R.string.admob_app_id));
    bannerAd = findViewById(R.id.adView);
    bannerAd.loadAd(adRequestBanner);
    bannerAd.setAdListener(new AdListener() {
    @Override
    public void onAdLoaded() {
    bannerAd.setVisibility(View.VISIBLE);
    }
    @Override
    public void onAdFailedToLoad(int error) {
    bannerAd.setVisibility(View.GONE);
    }
    });

XML：

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

</android.support.constraint.ConstraintLayout>

Logcat错误：

    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1445)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.ads.AdView.loadAd(com.google.android.gms.ads.AdRequest)' on a null object reference
    at com.vossendesign.stickerstore.MainActivity1.onCreate(MainActivity1.java:98)
    at android.app.Activity.performCreate(Activity.java:7326)
    at android.app.Activity.performCreate(Activity.java:7317)

横幅广告不适用于ConstraintLayout

0 个答案: