关闭网络后导致java.lang.NullPointerException的AdWhirl
关闭网络后导致java.lang.NullPointerException的AdWhirl
提问于 2012-05-17 11:08:32
我在我的一个应用中使用了adwhirl和Admob，在发布后，我们从AdWhirl中得到了很多错误，它很容易像这样重现：
广告出现后，我关闭wifi，等待广告超时，然后按back按钮退出应用程序。
然后可以从this.and下载appear.the src的错误，异常如下：
05-17 11:00:13.265: E/AndroidRuntime(12482): java.lang.RuntimeException: Unable to destroy activity {me.test.admob/me.test.admob.AdWhirlTestActivity}: java.lang.NullPointerException
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3112)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3130)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.ActivityThread.access$1200(ActivityThread.java:123)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1180)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.os.Looper.loop(Looper.java:137)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.ActivityThread.main(ActivityThread.java:4424)
05-17 11:00:13.265: E/AndroidRuntime(12482): at java.lang.reflect.Method.invokeNative(Native Method)
05-17 11:00:13.265: E/AndroidRuntime(12482): at java.lang.reflect.Method.invoke(Method.java:511)
05-17 11:00:13.265: E/AndroidRuntime(12482): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
05-17 11:00:13.265: E/AndroidRuntime(12482): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
05-17 11:00:13.265: E/AndroidRuntime(12482): at dalvik.system.NativeStart.main(Native Method)
05-17 11:00:13.265: E/AndroidRuntime(12482): Caused by: java.lang.NullPointerException
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.webkit.WebView.requestFocus(WebView.java:7650)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.requestFocus(ViewGroup.java:2113)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.View.requestFocus(View.java:5323)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewRootImpl.clearChildFocus(ViewRootImpl.java:2200)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.removeViewInternal(ViewGroup.java:3591)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.removeViewInternal(ViewGroup.java:3561)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.view.ViewGroup.removeView(ViewGroup.java:3509)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:998)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1080)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.support.v4.app.FragmentManagerImpl.dispatchDestroy(FragmentManager.java:1843)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.support.v4.app.FragmentActivity.onDestroy(FragmentActivity.java:314)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.Activity.performDestroy(Activity.java:4629)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1079)
05-17 11:00:13.265: E/AndroidRuntime(12482): at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3099)
05-17 11:00:13.265: E/AndroidRuntime(12482): ... 11 more在我的测试之后，我发现只有在ViewPager中使用adwhirl和ListFragment时才会出现这个异常，如果我只在ListFragment中使用，或者在ViewPager中使用Fragment，它是正常工作的。但是我仍然想知道哪里出了问题，以及我如何解决这个异常。
任何答案都将不胜感激。
回答 1
Stack Overflow用户
发布于 2012-07-11 00:00:00
始终检查连接到服务的对象的内容
if(conection !=null){
execute();
}因为您使用的webView总是在执行之前检查您的电话连接是否打开，所以这应该会停止空指针
如果没有代码示例，很难给出更好的见解
但是您可以使用连接性管理器进行检查，下面是如何检查wifi的一个示例。
public boolean isOnWifi(Context context) {
ConnectivityManager connManager = (ConnectivityManager) context
.getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connManager
.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (mWifi.isConnected()) {
return true;
}
return false;
}要查看是否有蜂窝连接，只需将ConnectivityManager.TYPE_WIFI更改为ConnectivityManager.TYPE_MOBILE
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/10629329
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