Device iOS10 , the navigationbar is heighter.

[XiangNanLi]

1. I use the code that it judge the version.
   But the new code does not judge the version.
   Now if the new code and the device version is ios10, the navigationbar is hegihter.
2. I set the backgroundcolor in the "ViewDidAppear"
   If the controller is the navigationController's rootViewController , the navigationBar will move up 20.
   But I set the backgroundColor in "viewDidLoad" , the navigationBar is normal.

I donot know why...