如果文件成功下载,我必须更新片段中的列表视图。所以在我的下载管理器的广播接收器我注册这个新的广播接收器:从广播接收器更新片段中的列表视图
Intent intent = new Intent();
intent.setAction("CONTENTS_NOTIFICATION");
context.sendBroadcast(intent);
而且在我onCreateView片段我添加以下代码以注册接收器:
IntentFilter filter = new IntentFilter("CONTENTS_NOTIFICATION");
getActivity().getApplicationContext().registerReceiver(myReceiver, filter);
则:
private BroadcastReceiver myReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
SQLiteDatabase db = DatabaseManager.getInstance(getActivity()).getWritableDatabase();
c = SelectedExperience.getSelectedExperiences(db);
String id_esperienza = "Selected Experience";
if (c.getCount() != 0) {
id_esperienza = c.getString(c.getColumnIndex(SelectedExperience.ID_ESPERIENZA));
}
populateListview(v, id_esperienza);
}
};
,并在年底:
public void onDestroyView() {
super.onDestroyView();
getActivity().getApplicationContext().unregisterReceiver(myReceiver);
}
我必须为两个不同的片段添加两个这些广播接收器。在第一个,一切正常。如果应用程序的用户是在片段,它更新,而在第二个片段我得到了这些错误:
03-15 07:32:40.474: E/AndroidRuntime(1692): FATAL EXCEPTION: main
03-15 07:32:40.474: E/AndroidRuntime(1692): java.lang.RuntimeException: Error receiving broadcast Intent { act=CONTENTS_NOTIFICATION flg=0x10 } in [email protected]
03-15 07:32:40.474: E/AndroidRuntime(1692): at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:768)
03-15 07:32:40.474: E/AndroidRuntime(1692): at android.os.Handler.handleCallback(Handler.java:725)
03-15 07:32:40.474: E/AndroidRuntime(1692): at android.os.Handler.dispatchMessage(Handler.java:92)
03-15 07:32:40.474: E/AndroidRuntime(1692): at android.os.Looper.loop(Looper.java:137)
03-15 07:32:40.474: E/AndroidRuntime(1692): at android.app.ActivityThread.main(ActivityThread.java:5191)
03-15 07:32:40.474: E/AndroidRuntime(1692): at java.lang.reflect.Method.invokeNative(Native Method)
03-15 07:32:40.474: E/AndroidRuntime(1692): at java.lang.reflect.Method.invoke(Method.java:511)
03-15 07:32:40.474: E/AndroidRuntime(1692): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
03-15 07:32:40.474: E/AndroidRuntime(1692): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
03-15 07:32:40.474: E/AndroidRuntime(1692): at dalvik.system.NativeStart.main(Native Method)
03-15 07:32:40.474: E/AndroidRuntime(1692): Caused by: java.lang.NullPointerException
03-15 07:32:40.474: E/AndroidRuntime(1692): at sample.actionscontentview.fragment.ContentsFragment.populateListview(ContentsFragment.java:194)
03-15 07:32:40.474: E/AndroidRuntime(1692): at sample.actionscontentview.fragment.ContentsFragment.access$0(ContentsFragment.java:111)
03-15 07:32:40.474: E/AndroidRuntime(1692): at sample.actionscontentview.fragment.ContentsFragment$1.onReceive(ContentsFragment.java:107)
03-15 07:32:40.474: E/AndroidRuntime(1692): at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:758)
03-15 07:32:40.474: E/AndroidRuntime(1692): ... 9 more
和代码是一样的!我无法弄清为什么它不起作用。它说populatelistView存在问题,但如果不从广播接收器调用,那么相同的函数在片段内工作正常。
我可以在此两个片段之间的想法唯一的区别是在更新工作之一是当应用程序启动的第一个打开。
什么是行号。 194并发布代码为populateListView – Atrix1987 2013-03-15 07:42:46
我的不好...错误是在populatelistView,特别是我传递错误的观点!所以代码工作正常! – phcaze 2013-03-15 08:16:58