viewdidload

问题 Does the addSubview method actually load the view into the application or not? The reason I am asking is because I have two two views in my application. The application delegate adds the two views as subviews and then brings one of the views up front. Now, I have a print statement in each of the viewDidLoad methods for each view. When I run the application, the application delegate loads the views as subViews and as each view is loaded, I actually see the console print out the statements that

问题 Maybe someone could tell me why when launch my app in the second time (after pressing the home button) the method viewDidLoad: is not being called? 回答1: On iOS 4 apps are no longer exited when pressing the home button. They are moved out of RAM, paused and then continued when you re-enter them, not launched again. 回答2: In iOS4 there is: (void)applicationDidBecomeActive:(UIApplication *)application { } Which is called when the application becomes active (out of background) you could call

问题 I have a simple slider app. When the slider is changed, the new value is displayed in a UILabel. That works great! When that view is loaded though the label is blank. I want the sliderValue.text to be equal to the default slider value. Here is my code right now (along with my previous attempt): -(IBAction)sliderValue:(UISlider *)sender { sliderLabel.text = [NSString stringWithFormat:@"%g", roundf(slider.value)]; } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after

问题 on one viewController of my app there is a long list of 20 or so buttons added programmatically, all which i want to call the same method, but to identify themselves through their button tag, but i ran into a problem that has set me back a few hours of research and attempts.The basic problem is i dont quite know how to access a programmatically created button in any other method than the method that they were initialized in. My questions summerized: 1) if i were to create the button in the

问题 I was doing some testing and debugging of my Iphone app today and encountered some strange behaviour. In my MainView I have two modal views and when showing one of these using presentModalViewController I noted that the viewDidUnload method of my MainView was called while it was not happening when showing the other. It was the same case for the viewDidLoad method (of MainView ) while closing the subviews. I inspected the two methods for opening and closing the subviews and the only difference

问题 Okay. If you have two viewControllers and you do a modal Segue from the first to the second, then you dismiss it with [self dismissModalViewControllerAnimated:YES]; it doesn't seem to recall viewDidLoad. I have a main page (viewController), then a options page of sorts and I want the main page to update when you change an option. This worked when I just did a two modal segues (one going forward, one going back), but that seemed unstructured and may lead to messy code in larger projects. I

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: initWithNibName VS viewDidLoad I'm new at iOS development. I would just like to know the main differences between these 2 functions ? Thanks for your help 回答1: viewDidLoad Is called when the view loads and is initiated/Unarchived and loaded into the memory. This is a great customisation stop. initWithNibName: Is used for initializing a certain class ( it is an overriden init method) with a xib file's name, the

问题 This question already has answers here : iOS: What is the difference between -init and -viewLoad of a ViewController? (3 answers) Closed 6 years ago . What is the general guideline for the difference between the types of code (object allocation, setting up ui elements, network calls, etc.) that should go in the init method vs. a viewDidLoad type method for a view controller? 回答1: Init => call at/use for initialize your ViewController and Initialize only for UIViewController and not it's views

问题 What is the difference between the two methods didFinishLaunchingWithOption and viewDidLoad ? The former is a method of AppDlegate.m and the latter is a method of ViewController.m , but both of them perform the same mission of loading the UIs onto the view. 回答1: The application:didFinishLaunchingWithOptions: is a UIApplicationDelegate protocol method that gets called when iOS has finished setting up an area for your App to run and is the insertion point for you, the developer, to load a view

问题 Problem Summary My mainVC --> second VC transtion appears to run twice. However, what's odd is that the second VC's viewDidLoad only runs once. This is the only transition in my project that has this problem. I have researched this and found load-twice issues but none are a match to my transition twice but load once scenario. Common issues, like someone having added two segues in the storyboard, do not appear in my project: In my first/root view controller (called mainVC) I programmatically