SurfaceView.onAttachedToWindow中的NullPointerException(SurfaceView.java:207)

我从SurfaceView.onAttachedToWindow获得了这个异常.看起来SurfaceView试图引用mParent,但它是null.有谁知道为什么不设置父级但是会调用onAttachedToWindow？

我正在使用SurfaceView进行相机预览.我有一个ViewGroup,它是从活动的根视图中添加/删除的.ViewGroup内部是SurfaceView和WebView.

以下是ViewGroup的代码:http://pastebin.com/eSyZ3v3P,以下是显示/隐藏相机的代码:http://pastebin.com/5iaEFCQr

任何帮助将非常感激.

这是完整的堆栈跟踪:

java.lang.NullPointerException
    at android.view.SurfaceView.onAttachedToWindow(SurfaceView.java:207)
    at android.view.View.dispatchAttachedToWindow(View.java:11755)
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1199)
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:998)
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4212)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
    at android.view.Choreographer.doCallbacks(Choreographer.java:555)
    at android.view.Choreographer.doFrame(Choreographer.java:525)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
    at android.os.Handler.handleCallback(Handler.java:615)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:4745)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
    at dalvik.system.NativeStart.main(Native Method)

- 编辑 -

对不起,我忘了提,我不知道重现异常的步骤.每次运行应用程序时代码都有效,但是我将这些异常从Samsung Galaxy Tab 3发送到我的记录器.问题不一致.