“Attempting to load the view of a view controller while it is deallocating… UISearchController"

出现的问题原因，从一个控制器modal到一个带有搜索控制器，然后从搜索控制器返回的时候，会出现这个警告

Attempting to load the view of a view controller while it is deallocating is not allowed and may result in undefined behavior ()

解决办法：
Objective-C...

-(void)dealloc { 
    [searchController.view removeFromSuperview]; // It works!
}

Swift 3...

deinit {
    self.searchController.view.removeFromSuperview()
}

引用

Attempting to load the view of a view controller while it is deallocating… UISearchController