uiviewcontroller

问题 Summary of question UINavigationControllerDelegate:didShowViewContoller makes it possible to get notified whenever any view controller has been displayed (as opposed to being loaded), provided its within the context of a navigation stack. I want to know if such observation is possible for all view controllers if there isn't a navigation stack. More background I have an app where view controllers can suddenly appear based upon timers and local notifications firing, thus their appearance is

问题 I'm trying to pop to a viewcontroller which I believe is at index 0. My ViewController name is HomeVC. self.navigationController!.popToViewController(self.navigationController!.viewControllers[0] as! UIViewController, animated: true) However, the code above only pops me back to the most recent viewcontroller. Not sure why it's not going to my HomeVC viewcontroller. Is their a way I can use the ViewController Name to pop to it? 回答1: Try this: for (var i = 0; i < self.navigationController?

问题 This is what I'm trying to do... I have one view controller that needs to dynamically display different subviews based on the presence of some data. Here is a simple mockup. Each colored block represents a unique subview . Sometimes the green block needs to be at the top, sometimes the green block won't display at all, sometimes the light blue block will be something different, etc. Each subview has interactive elements, so I've been creating and adding them like so: Defining a new view

问题 Solved. Ridiculously embarrassing. I wasn't using an instance variable, I declared it outside of curly braces in the implementation. Really struggling. I have a view controller that manages an animated countdown timer. The animation is using recursive UIView animation and a simple int ivar that gets decremented. Something like the following (this is a simplified snippet): - (void) animate { [UIView animateWithDuration:0.75f delay:0.25f options:UIViewAnimationCurveEaseInOut animations:^{ aView

问题 when i load my viewController i used "viewDidLoad"method to init my view ,but this take much time to make the view appeared .So i had the idea to use "viewDidAppear" method to accelerate the appearance of my view but the load of the informations about my view are now loaded to the memory every time that i push my view (which is normal) or i pop to it(and there is my problem) Have you an idea? 回答1: Create a background task that is started in viewDidLoad and just updates the GUI when it's

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 3 years ago . I wanted to see what the best practice(s) of accessing UIViewController methods from GameScene is/are. Right now I have been using NSNotificationCenter, but I don't want to use this due to specific functionality that I am trying to achieve. Also, if there are not any other

问题 Is there anyway to create a custom alertController that fit the width of the screen ? I tried several things before asking this question one of them is : let width:NSLayoutConstraint = NSLayoutConstraint(item: alertController.view, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: view.bounds.width ) alertController.view.addConstraint(width) But this line of code always makes a horizontal

问题 I've got a really strange bug in my project. I've got a UIScrollView as my main, big view. Inside of it, I have a UIViewController (not UITableViewController ) which has a UITableView instance variable, as well as some miscellaneous UIButtons . I have set the view controller's view frame to CGRectMake(0, 64, 320, 388) , as I have a tab bar above it (this is not functional yet). At first it works great and looks great, but once I present and dismiss a modalViewController (thus reloading the

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: [super viewDidLoad] convention Does it make a difference where I put [super viewDidLoad] within the viewDidLoad in my UIViewController? I.e., should it go at the beginning (before my code to set up the UIViewController) or the end )after my code to set up the UIViewController) of the method, or does it not make any difference? 回答1: You should usually call super as early as possible. Otherwise, the superclass may

问题 I have a UIViewController derived class which uses the method dismissModalViewControllerAnimated:(BOOL) , like this: [self dismissModalViewControllerAnimated:YES]; Since the compiler complains with a warning saying that this method is deprecated, I have changed it to the suggested replacement, dismissModalViewControllerAnimated:completion: , like this: [self dismissModalViewControllerAnimated:YES completion:nil]; But now, a get an error in that line of code saying "No visible @interface for