问题描述
我无法从IntentService生成通知(在通知区域中).获取NotificationManager时得到一个NullPointerException.问题出在上下文.
I am unable to generate the notification (in the notification area) from an IntentService. I get a NullPointerException while obtaining NotificationManager. The problem is with Context.
06-01 16:46:05.910: ERROR/AndroidRuntime(14745): Caused by: java.lang.NullPointerException
06-01 16:46:05.910: ERROR/AndroidRuntime(14745): at android.content.ContextWrapper.getSystemService(ContextWrapper.java:363)
06-01 16:46:05.910: ERROR/AndroidRuntime(14745): at com.Android.Main1.FileUploaderService.<init>(FileUploaderService.java:71)
代码行是:
mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
我尝试了getApplicationContext()，getBaseContext()，但无济于事.
I have tried getApplicationContext(), getBaseContext(), but to no avail.
有人可以让我知道这里是什么问题吗?如何从IntentService生成通知?
Could someone please let me know what is the problem here? How do I generate notifications from an IntentService?
其他信息:
我的应用程序中也有一个Service，并且来自那里的通知可以正常工作. IntentService不是由Activity启动的；它由服务启动.
Additional Info:
I also have a Service in my app, and notifications from there work properly. The IntentService is not started by an Activity; it is started by the Service.
推荐答案
将对getSystemService的调用移出构造函数，并移至onCreate.
Move your call to getSystemService out of the constructor and into onCreate.
ContextWrapper中的基本Context尚未设置，这导致NullPointerException.
The base Context in the ContextWrapper has not been set yet, which is causing the NullPointerException.
这篇关于来自IntentService的通知-NullPointerException，同时获取上下文的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！