小编Per*_*lce的帖子

我对getWritableDatabase()的调用遇到了问题.它返回一个NullPointerException.最奇怪的是,这个错误只是在我在Android清单中注释掉几行代码之后才开始发生的.现在项目又回到了原来的位置(我没有对这些部分进行评论,但它仍然会抛出NullPointerException).所以我检查了我的上下文并尝试了this.getBaseContext()和this.getApplicationContext().

使用getApplicationContext()将其发送到logcat:

08-12 09:24:20.042: E/AndroidRuntime(5572): FATAL EXCEPTION: main
08-12 09:24:20.042: E/AndroidRuntime(5572): java.lang.RuntimeException: Unable to instantiate service com.productivity.uptimeapp.NetService: java.lang.NullPointerException
08-12 09:24:20.042: E/AndroidRuntime(5572):     at android.app.ActivityThread.handleCreateService(ActivityThread.java:2395)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at android.app.ActivityThread.access$1600(ActivityThread.java:139)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1313)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at android.os.Looper.loop(Looper.java:137)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at android.app.ActivityThread.main(ActivityThread.java:5021)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at java.lang.reflect.Method.invokeNative(Native Method)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at java.lang.reflect.Method.invoke(Method.java:511)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
08-12 09:24:20.042: E/AndroidRuntime(5572):     at dalvik.system.NativeStart.main(Native Method)
08-12 09:24:20.042: E/AndroidRuntime(5572): Caused by: …