Any code you put inside of viewDidLoad should be able to run multiple times with out any issues. If you have code that only needs to run once for your controller use -awakeFromNib. The reason is because the view of the view controller can be unloaded and loaded multiple times. The code inside of viewDidLoad … Read more
viewDidLoad is called when the class is loaded however no ui elements have been initialised and therefore any attempt to reference them will be overwritten or unavaliable during the initialisation process which happens between the viewDidLoad and viewDidAppear calls. Once all ui element have been initalised and drawn viewDidAppear is called. viewDidLoad – Called after … Read more
I had this same issue when my app was first launching. What I found was that in my MainWindow.xib file, I was setting both my App Delegate’s viewController outlet, and my Window’s rootViewController outlet to my root view controller. When you build a View Based project file in Xcode, your App Delegate’s didFinishLaunchingWithOptions will be … Read more
Depending on what kind of actions you need to perform, there are several techniques: -(id)initWithFrame:(CGRect)frame – UIView’s designated initializer; always sent to a UIView to initialize it, unless the view is loaded from a nib; -(id)initWithCoder:(NSCoder *)coder – always sent to initialize a UIView whenever the view is loaded from a nib; -(void)awakeFromNib – sent … Read more
If you are overriding the method you should still call the method in the super. Even if the super class is not doing anything with it today, Apple might one day change the implementation and your code will mysteriously stop working. If you really don’t need to do anything in that method, leave it out … Read more
viewDidLoad is things you have to do once. viewWillAppear gets called every time the view appears. You should do things that you only have to do once in viewDidLoad – like setting your UILabel texts. However, you may want to modify a specific part of the view every time the user gets to view it, … Read more
The frame is not guaranteed to be the same in viewDidLoad as it will be when the view is eventually displayed. UIKit adjusts the frame of your view controller’s view prior to displaying it, based on the context in which will appear. The size is determined based on interface orientation and the dimensions of any … Read more