Wait_fences: failed to receive reply: 10004003

Wait_fences: failed to receive reply: 10004003 cause: the essence of this problem should be to directly modify the interface in a non-main thread
Solution: operations performed in the background or sub-threads must be performed in the main thread when refreshing the UI.

// Possible details:
1. Proxy method for implementing uialertview
-(Void) alertview :( uialertview *) alertview clickedbuttonatindex :( nsinteger) buttonindex {
}
2. Multiple buttons are generated in the viewdidload method. click the button to switch their selected status. This problem occurs.

//
[IPhone] [xcode] wait_fences: failed to receive reply: 10004003
An error warning like executing an animation before the view is displayed
For example, if you start uialertview without a rootviewcontroller and only a window, this warning will appear.