我的应用程序经常死(My app frequently dies)

我的应用程序经常死(My app frequently dies)

我不知道这是否是寻求帮助的正确方法，但我最近上传了一个应用程序到谷歌游戏商店。 这是我的应用程序的链接

提交的错误：

java.util.ConcurrentModificationException at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:573) at de.krissini.server.GamePanel.onDraw(GamePanel.java:230) at android.view.View.draw(View.java:15249) at android.view.SurfaceView.draw(SurfaceView.java:340) at android.view.View.updateDisplayListIfDirty(View.java:14185) at android.view.View.getDisplayList(View.java:14207) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3391) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3370) at android.view.View.updateDisplayListIfDirty(View.java:14145) at android.view.View.getDisplayList(View.java:14207) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3391) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3370) at android.view.View.updateDisplayListIfDirty(View.java:14145) at android.view.View.getDisplayList(View.java:14207) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3391) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3370) at android.view.View.updateDisplayListIfDirty(View.java:14145) at android.view.View.getDisplayList(View.java:14207) at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:273) at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:279) at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:318) at android.view.ViewRootImpl.draw(ViewRootImpl.java:2560) at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2382) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2012) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1084) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5990) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767) at android.view.Choreographer.doCallbacks(Choreographer.java:580) at android.view.Choreographer.doFrame(Choreographer.java:550) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5343) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)

omg现在需要更多文字blablabla对不起，请不要这样看

I don't know if this is the right way to ask for help, but I recently uploaded a app to the google play store. Here a link to my app

a submitted error:

java.util.ConcurrentModificationException at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:573) at de.krissini.server.GamePanel.onDraw(GamePanel.java:230) at android.view.View.draw(View.java:15249) at android.view.SurfaceView.draw(SurfaceView.java:340) at android.view.View.updateDisplayListIfDirty(View.java:14185) at android.view.View.getDisplayList(View.java:14207) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3391) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3370) at android.view.View.updateDisplayListIfDirty(View.java:14145) at android.view.View.getDisplayList(View.java:14207) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3391) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3370) at android.view.View.updateDisplayListIfDirty(View.java:14145) at android.view.View.getDisplayList(View.java:14207) at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3391) at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3370) at android.view.View.updateDisplayListIfDirty(View.java:14145) at android.view.View.getDisplayList(View.java:14207) at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:273) at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:279) at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:318) at android.view.ViewRootImpl.draw(ViewRootImpl.java:2560) at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2382) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2012) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1084) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5990) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767) at android.view.Choreographer.doCallbacks(Choreographer.java:580) at android.view.Choreographer.doFrame(Choreographer.java:550) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5343) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)

omg now it needs more text blablabla sorry, don't read this please

最满意答案

这将帮助您：它创建集合的浅表副本，并迭代副本而不是原始副本。

@Override public void onDraw(Canvas canvas) { if (canvas != null && getHolder().getSurface().isValid()) { bg.draw(canvas); player.draw(canvas); if (player.getPlaying()) { List<Smokepuff> copySmoke = new ArrayList<Smokepuff>(smoke); List<Missle> copyMissles = new ArrayList<Missle>(missles); for (Smokepuff sp : copySmoke) { sp.draw(canvas); } for (Missle m : copyMissles) { m.draw(canvas); } drawScore(canvas); } postInvalidate(); } }

但是你应该想到为什么它首先崩溃在这里。

当您尝试在迭代时修改集合时发生ConcurrentModificationException 。 你在多个线程中使用该集合吗？ 如果是，您应该考虑一些同步。 特别是在添加和删除操作时。

onDraw()会经常被调用，因此，由于性能问题，在每个调用中复制集合可能不是一个好主意 。 它会对你有所帮助，但我仍然建议检查你在不同线程中使用这些集合的所有地方。

This will help you: It creates shallow copy of your collections and iterates over copies instead the original ones.

@Override public void onDraw(Canvas canvas) { if (canvas != null && getHolder().getSurface().isValid()) { bg.draw(canvas); player.draw(canvas); if (player.getPlaying()) { List<Smokepuff> copySmoke = new ArrayList<Smokepuff>(smoke); List<Missle> copyMissles = new ArrayList<Missle>(missles); for (Smokepuff sp : copySmoke) { sp.draw(canvas); } for (Missle m : copyMissles) { m.draw(canvas); } drawScore(canvas); } postInvalidate(); } }

However you should think why it crashes here in the first place.

ConcurrentModificationException happens when you try to modify the collection while iterating over it. Do you use that collection in multiple threads? If yes, you should consider some synchronization. Especially when it comes to add and remove operations.

The onDraw() will be called very often, so making copies of collections in it's every call might not be a great idea due to performance issues. It will help you, but I still recommend to check all of the places where you use those collections in different threads.