ios问题bug收录——1

 **[2713:59682] *** Assertion failure in -[MBProgressHUD show:], /Users/lu/Desktop/****/Pods/MBProgressHUD/MBProgressHUD.m:248

 **[2713:59682] *** Terminating app due to uncaught exception ‘NSInternalInconsistencyException‘, reason: ‘MBProgressHUD needs to be accessed on the main thread.‘

‘MBProgressHUD needs to be accessed on the main thread.‘这个错误主要翻译成，MBProgressHUD必须在主线程上运行。

而我是与js交互之后back回去的。。可见webView加载完毕，与js交互占用的不是主线程？？？？

解决办法 ：

　　　　 dispatch_async(dispatch_get_main_queue(), {

self.navigationController!.popViewControllerAnimated(true)

})