Question

我不知道这是否是寻求帮助的正确方法，但我最近将应用程序上传到了Google Play商店。这是指向my app

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)

现在需要更多文字blablabla对不起，请不要读这个

Answer 1

这将有助于您：它创建了集合的浅表副本，并重复了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();
    }
}

然而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会发生

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，在每次调用的每次调用中制作集合副本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。

Answer 2

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

我的应用程序经常死

2 个答案: