Question

您好我在我的应用程序中添加粉丝横幅时出现问题我收到错误消息我在我的布局中添加了横幅容器

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.kimali.bhirod.MainActivity">

<LinearLayout
    android:id="@+id/banner_container"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:orientation="vertical"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    />

然后我实例化广告 - 视图并将其加载到我的活动中

public class MainActivity extends AppCompatActivity {

private AdView adView;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Instantiate an AdView view
    adView = new AdView(this, "153676755260608_153679028593714", AdSize.BANNER_HEIGHT_50);

    // Find the Ad Container
    LinearLayout adContainer = (LinearLayout) findViewById(R.id.banner_container);

    // Add the ad view to your activity layout
    adContainer.addView(adView);

    // Request an ad
    adView.loadAd(); setContentView(R.layout.activity_main);

但当我尝试在我的设备上测试代码时，我收到此错误

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.kimali.bhirod/com.kimali.bhirod.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.LinearLayout.addView(android.view.View)' on a null object reference

谢谢

Answer 1

您的setContentView(R.layout.your_layout)中没有onCreate()。如果不膨胀，布局findViewById将返回null。

在ConstrantLayout上添加Facebook观众网络横幅的Eror

1 个答案: