adView引发空指针异常

Question

请找到下面的代码，adView给出了nullpointerexception。

    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);

    // Prepare the Interstitial Ad
            interstitial = new InterstitialAd(MainActivity.this);
            // Insert the Ad Unit ID
            interstitial.setAdUnitId("ca-app-pub-6117491189465387/7628536955");

    //Locate the Banner Ad in activity_main.xml
    AdView adView = (AdView)findViewById(R.id.adView);

    // Request for Ads
    AdRequest.Builder adRequestBuilder=new AdRequest.Builder();

    // Add a test device to show Test Ads
        adRequestBuilder .addTestDevice(AdRequest.DEVICE_ID_EMULATOR);
        adRequestBuilder.addTestDevice("abcd").build();

    // Load ads into Banner Ads


     adView.setAdSize(AdSize.BANNER);
        adView.setAdUnitId("ca-app-pub-6117491189465387/7628536955");
        adView.loadAd(adRequestBuilder.build());

    interstitial.setAdListener(new AdListener() {
        public void onAdLoaded() {
            // Call displayInterstitial() function
            displayInterstitial();
        }

    });

2天后我就被打动了，请告诉我哪里弄错了

Answer 1

我没看到你的setContentView()方法()。adview可能为空，因为您要么没有设置要使用的布局，要么在初始化adview之后调用了setContentView()。你应该有这个：

 setContentView(R.layout.activity_main);
AdView adView = (AdView)findViewById(R.id.adView);

如果我错了，请发布onCreate()方法的完整内容，您的logcat堆栈跟踪和布局文件