我收到了很多关于postNotificationName的崩溃日志：
我正在做的是在viewdiddisar上注册viewdidappear和removeObserver的通知。他们中的大多数都是在sendDelegateAnimationDidStop之后崩溃，什么调用此方法并导致通知崩溃？谢谢大家。
Thread : Crashed: com.apple.main-thread
0 libsystem_platform.dylib 0x3b2b04da _platform_memmove$VARIANT$Swift + 185
1 ??? 0x00000008
2 CoreFoundation 0x30106b25 _CFXNotificationPost + 1076
3 Foundation 0x30af1cc5 -[NSNotificationCenter postNotificationName:object:userInfo:] + 72
4 UIKit 0x32a38655 -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 816
5 UIKit 0x32a382ef -[UIViewAnimationState animationDidStop:finished:] + 66
6 QuartzCore 0x32682e0b CA::Layer::run_animation_callbacks(void*) + 234
7 libdispatch.dylib 0x3b180d3f _dispatch_client_callout + 22
8 libdispatch.dylib 0x3b1836c3 _dispatch_main_queue_callback_4CF + 278
9 CoreFoundation 0x3019b681 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
10 CoreFoundation 0x30199f4d __CFRunLoopRun + 1308
11 CoreFoundation 0x30104769 CFRunLoopRunSpecific + 524
12 CoreFoundation 0x3010454b CFRunLoopRunInMode + 106
13 GraphicsServices 0x3502e6d3 GSEventRunModal + 138
14 UIKit 0x32a63891 UIApplicationMain + 1136
15 App 0x00078c2d main (main.m:21)