In general, you try to figure out what the code was doing, and what objects that you directly or indirectly defined/created/modified that it might be referencing. Then study the code that creates/modifies those objects to see if you can intuit which values might be set to null when they shouldn't be, or which values might be leading the code to look at a pointer that it shouldn't try to look at.
I haven't done this a lot, but have done it a few times, and it's usually easier than you think to intuit the cause -- you just have to get over being intimidated by the problem. It helps, of course, if you can actually look at the source for the failing class to see what it was referencing at that point. On May 3, 1:55 pm, vatsee <vat...@gmail.com> wrote: > Hi gurus, > > I am working on an app that supports bidirectional audio-video > communication. As part of that, the video GUI screen uses > MediaRecorder for recording outgoing video & uses two surfaceView > subclasses to display preview & incoming video. > > During the video call, I am seeing a (random) NPE. This trace (listed > below) does not show any of my app code. > I am not sure how to debug this issue. > > Has anybody seen anything similar to this? Appreciate if I can get > some pointers on how to debug this issue. > > java.lang.NullPointerException > at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1366) > at android.view.ViewGroup.drawChild(ViewGroup.java:1638) > at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) > at android.view.ViewGroup.drawChild(ViewGroup.java:1638) > at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) > at android.view.View.draw(View.java:6743) > at android.widget.FrameLayout.draw(FrameLayout.java:352) > at com.android.internal.policy.impl.PhoneWindow > $DecorView.draw(PhoneWindow.java:2058) > at android.view.ViewRoot.draw(ViewRoot.java:1432) > at android.view.ViewRoot.performTraversals(ViewRoot.java:1174) > at android.view.ViewRoot.handleMessage(ViewRoot.java:1752) > at android.os.Handler.dispatchMessage(Handler.java:99) > at android.os.Looper.loop(Looper.java:123) > at android.app.ActivityThread.main(ActivityThread.java:4627) > at java.lang.reflect.Method.invokeNative(Native Method) > at java.lang.reflect.Method.invoke(Method.java:521) > at com.android.internal.os.ZygoteInit > $MethodAndArgsCaller.run(ZygoteInit.java:858) > at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) > at dalvik.system.NativeStart.main(Native Method) > > Many thanks! -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
