从 ArrayList 中删除某些内容后，ActivityThread 崩溃程序

Question

好的，所以我的程序中有这个方法，我从 ArrayList 中删除一个对象。 （方法在这篇文章的底部）。它也做了一些其他的事情，但经过大量调试后，我发现正是这一行导致程序崩溃：

myTrackedEventsList.remove(currentEvent);

我通过尝试在有和没有这条线的情况下运行块来测试这一点。没有这条线，它不会崩溃。 有趣的是，这行代码并没有直接让程序崩溃，实际上整个方法都跑完了，然后又回到了我调用它的地方，这是我的

public void onClick(View v) {}

退出onClick方法后跳转到

Activity.java -> View.java -> ActivityThread.jaca -> Handler.java and Looper.java

现在，我真的不知道这些类是做什么的，我也不知道它们为什么会导致我的程序崩溃……是 ActivityThread.java 导致程序崩溃。

您能帮我弄清楚程序崩溃的原因吗？ =)

非常感谢您的任何帮助！ 所有代码都可以在这里找到： https://github.com/smholsen/BigDayCountdown/tree/master/app/src/main/java/com/simonm/bigdaycountdown

这是我得到的错误代码：

12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime: FATAL EXCEPTION: main
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime: Process: com.simonm.bigdaycountdown, PID: 17346
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:394)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.AbsListView.obtainView(AbsListView.java:2344)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.ListView.makeAndAddView(ListView.java:1864)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.ListView.fillDown(ListView.java:698)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.ListView.fillFromTop(ListView.java:759)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.ListView.layoutChildren(ListView.java:1673)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.AbsListView.onLayout(AbsListView.java:2148)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.View.layout(View.java:15691)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewGroup.layout(ViewGroup.java:4967)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:1067)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.View.layout(View.java:15691)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewGroup.layout(ViewGroup.java:4967)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.View.layout(View.java:15691)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewGroup.layout(ViewGroup.java:4967)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.View.layout(View.java:15691)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewGroup.layout(ViewGroup.java:4967)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.View.layout(View.java:15691)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewGroup.layout(ViewGroup.java:4967)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.View.layout(View.java:15691)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewGroup.layout(ViewGroup.java:4967)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.View.layout(View.java:15691)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewGroup.layout(ViewGroup.java:4967)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2093)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1850)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1063)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5807)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.Choreographer.doCallbacks(Choreographer.java:580)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.Choreographer.doFrame(Choreographer.java:550)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:739)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:95)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:135)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5321)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1016)
12-03 21:04:08.365 17346-17346/com.simonm.bigdaycountdown E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)
12-03 21:04:08.459 17346-17346/com.simonm.bigdaycountdown I/Process: Sending signal. PID: 17346 SIG: 9

这是 deleteEvent() 方法：

    protected void deleteEvent(){

    if (currentEvent != null) {
        eventNames.remove(currentEvent.getEventTitle());

        //TODO: This line somehow crashes the program long after it has been executed, I have no idea why.
        myTrackedEventsList.remove(currentEvent);

        currentEvent.delete();
        currentEvent = null;
        Collections.sort(myTrackedEventsList);
        if (myTrackedEventsList.size() > 0){
            currentEvent = myTrackedEventsList.get(0);
            updateUI();
        }
        updateEventDrawer();
    }

    if (myTrackedEventsList.size() == 0){
        resetUI();
        updateEventDrawer();
        noEventsUI();
        findViewById(R.id.getStartedText).setVisibility(View.VISIBLE);

        ((ImageView) findViewById(R.id.background)).setImageResource(R.mipmap.background);
    }


}

Answer 1

您的 myTrackedEventsList 似乎为空。检查您将数据添加到该数组的位置并确保您正在填充它。

Answer 2

这可能是由 Log.i(someString, null);

String.valueOf(null) //return null

Log.i("eventListBEFORE", String.valueOf(myTrackedEventsList));