Android ViewGroup崩溃：尝试从空对象引用上的字段'int android.view.View.mViewFlags'读取 [英] Android ViewGroup crash: Attempt to read from field 'int android.view.View.mViewFlags' on a null object reference

问题描述

我们发现了几种由后端日志记录监控报告的此类崩溃案例。似乎崩溃与特定的UX失败无关。从报告中，没有迹象表明我们自己的课程如何参与（没有任何课程名称的迹象）。以下是典型崩溃的示例：

We have found several cases for this kind of crashes reported by backend logging monitoring. It seems the crashes do not tie to particular UX failure. And from the reports, there is no sign of how our own classes being involved(no sign of any of our classes names). Here is an example of typical crashes:

java.lang.NullPointerException: Attempt to read from field 'int android.view.View.mViewFlags' on a null object reference 
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3357) 
at android.view.View.updateDisplayListIfDirty(View.java:14288) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3549) 
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3528) 
at android.view.View.updateDisplayListIfDirty(View.java:14253) 
at android.view.View.getDisplayList(View.java:14315) 
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:2561) 
at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2377) 
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2007) 
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1086) 
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6453) 
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:846) 
at android.view.Choreographer.doCallbacks(Choreographer.java:647) 
at android.view.Choreographer.doFrame(Choreographer.java:601) 
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:829) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5254) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:927) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:713) 

有谁知道是否有相关的bug记录Android代码？

Does anyone know whether there is related bug logged against Android code?

推荐答案

可能的解决方案

我有这个同样的问题。我设置了一个动画，并在 onAnimationEnd 我删除了已经设置动画的对象，这是问题开始的时候。我做的是设置一个异步 Runnable ，等待动画停止后100毫秒，然后再删除动画对象：

Possible Solution

I had this same issue. I setup an animation and in onAnimationEnd I was removing the object that had been animated which is when problems started. What I did was setup an asynchronous Runnable to wait 100 milliseconds after the animation had stopped before removing the animated object:

以前动画的对象是 this._loader

private void removeLoader() {
    final ContentContainer self = this; // "CustomContainer" needs to match the type of `this`
    Handler h = new Handler();
    h.postAtTime(new Runnable() {
        @Override
        public void run() {
            MainActivity.instance.runOnUiThread(new Runnable() { 
                @Override
                public void run() {
                    try {
                        if(self._loader == null) {
                            // there is no loader. quit now while you still have the chance!!
                            return;
                        }
                        while(self._loader.getParent() != null) {
                            removeView(self._loader);
                        }
                    } catch(Exception e) {
                        Crashlytics.logException(e);
                        e.printStackTrace();
                    }

                    self._loader = null;
                }
            });
        }
    }, 100);
}

干杯

Cheers

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