Ok hopefully this is an easy question:
I have a main viewcontroller that is loaded by the app delegate at application startup.
This viewcontroller has some code in 'viewDidLoad' to create some non view type based objects (some sound/data objects). Aside from that it also loads a UIView.
The sound/data objects take a while to create, but the app is quite functional without them for a start - so I want to load these objects after the UIView has loaded, but can't seem to figure out how.
I have tried moving the appropriate code to viewDidAppear, but this is still called before the UIView actually appears on screen. Is there a function that is called after the viewcontroller actually starts displaying UIViews, or any other way to achieve what I want?
Any help would be much appreciated - thanks!
In case anyone else has a similar problem, I found a way to solve it: use NSThread to load things in the background without pausing everything else.
There's a good simple example here: http://www.iphoneexamples.com/.
Related
Most of the iOS apps I use are very responsive, when I tap on an element it goes to the next view right away. In my app, some of my view controllers take 0.5-1.0 second to load.
My code is all in the viewDidLoad method and I'm pretty sure that's the problem but I can't move anything out since I need every single element that I instantiate.
A solution I thought is to move all the work I do in viewDidLoad in a thread then call the main thread when I'm ready to call addSubview, would that work even if UIKit is not thread safe? Or is there something else I'm missing?
Try to move some code you might have in viewDidLoad to viewdidAppear. viewDidAppear is being called once the view is presented. If you have to make some hard work, do it there and maybe show aa spinner somewhere while you do that.
What are you exactly doing in viewDidLoad? Btw remember that a view is only loaded when you need it, if you want to switch between views faster I can suggest you to create an initializion phase where you call -view on all the view controller you want to show, maybe helped with a spinner or a progress bar. but pay attention this would work only with intensive loading task and not memory consuming tasks. It sounds very strange your request, so is better the you try to explain better why your viewDidLoad is so slow, maybe there is something wrong.
Define your UI elements in Xcode as part of designing the interface. That way, Xcode can compile your storeyboard or xib files into the rapidly loading binary form.
I have a simple UIViewController whose view is created via a Nib. Here's the structure of the Nib:
And a screenshot of the layout:
Whatever the previous view (there are 2 possibilities), there is significant stutter/lag when transitioning to this view. Even the keyboard animation is lagged. Also, this is only on an actual device.
I've tried removing the MKMapView to see if that was the case, but it didn't make a difference.
Is the Nib too complex? Should I load everything via code? I'm not sure what it could be, but its really annoying, especially when the rest of the app is super crisp.
As far as code goes, its nothing special: just alloc/init a view, push it onto a UINavigationController, etc. Nothing in the viewWillAppear:/viewWillDisappear:.
Coming from Reddit, where you posted code (probably want to do that here too):
My guess would be the lag is coming from the section from line 44 through 80ish, where you build the overlay. Something in there might be taking longer than you think (Spotpoint unSerialize sounds fishy). You typically want to do as little work as possible in viewDidLoad, since that is called as the UI is transitioning to the new view controller.
Try throwing that code into a GCD queue or running it in the background, and see if that helps the loading stutter.
I am starting to learning Cocos2D for iPhone. I see the basic template has a viewController but when it runs it loads HelloWorldLayer, instead of the viewController view.
When you work with a viewController, you used to have the main logic for that controller on the .m, but as Cocos2D works in another way I wonder where should I put the main logic code.
What I mean is this. Developing with Cocos2D I will have a bunch of these "layer" files and as I pass the scenes, one of these files will be active at one time but now imagine that I am building an app that has in-app purchases or coredata. I have to have one central place where this common logic to handle sales and the database should reside. Where is the best practice? To put it on the viewController Cocos2D creates or what? How do you do that?
Where do I put the code so it will initialize when the app runs and before showing the first scene?
thanks
The startup code in Cocos2D is in the app delegate applicationDidFinishLaunching method. So you may want to initialize your loading code there.
The issue you're experiencing may be due to the incorrect setup of the view controller by Cocos2D, which leads to the view controller's viewDidLoad method not to be called. You can call that manually from applicationDidFinishLaunching however, after the line: rootViewController.view = glView
You'll find plenty of Tutorials that shed more light on this here: http://www.raywenderlich.com/
I've got a custom UIViewController that loads a xib. The first time it's instantiated, it takes some time before it appears. Is there an elegant way to preload it, so it won't do this? I tried just creating it and immediately after release it. That didn't seem to work. I suppose if I wanna do it that way, I'd have to add it to the main window (for example), and then remove it. But in any case, that solution seems a bit ugly. Any other way?
Try creating it and calling [controller view]. This will load its xib and create and hook up its view outlet, etc.
Hey all, I'm completely stumped with this iPhone problem.
This is my first time building a view programmatically, without a nib. I can get the view displaying things just fine, but the darn ViewController isn't responding to touches the way it used to in programs where I used a nib. I should add that in the past, I started with the View-Based Application template, and this time I used the Window-Based Application template.
My thinking is that the View-Based template does something magical to let the iPhone know where to send the touch events, but I can't figure out what that would be even after several hours of bumbling around Google. Or I could be looking in an entirely wrong place and my troubles are related to something else entirely. Any thoughts?
There's nothing magical in the view-based template. The most likely reasons for failure to respond to touches are:
You've messed with touchesBegan:withEvent:, userInteractionEnabled, exclusiveTouch or something else, thinking you need to mess with these (generally you don't; the defaults are generally correct)
You created a second UIWindow
You put something over the view (even if it's transparent)
Simplify your code down to just creating a view programatically that responds to a touch and nothing else. It should be just a few lines of code. If you can't get that working, post the code and we'll look at what's going on.
Problem solved. touchesEnded != touchedEnded.
That'll teach me to program without my glasses on.
Another possible scenario for failure in response to touches is when your VC frame is not predefined and its boundaries are actually exceeding the window placeholder. It happens a lot when you just forget to define the frame property for the VC.
Once you define it correctly - User interaction returns to normal.
Good luck !