I’ve often wondered how to use those efficiently, and I’ve just found out how to do it. As always, they’re not difficult to implement – but not documented in a way that simple folk like me can understand it. Be that as it may… Preprocessor Macros can be useful if you’d like to compile two […]
Here’s how we check that: // if we’re an iPad if ([[UIDevice currentDevice]userInterfaceIdiom] == UIUserInterfaceIdiomPad) { // do some iPad or iPad Mini specific stuff } else { // we’re on iPhone or iPod Touch } Alternatively you can check the same method for UIUserInterfaceIdiomPhone instead, which is returned when you’re on an iPhone or […]
You can hide (and show) navigation bars and toolbars from your UINavigationController with extremely funky animations, much like we see in the Photos app on iOS. In the app, when you single-tap the screen, both top and bottom toolbars disappear. Here’s how we do that: Provided you have your view controller embedded in a UINavigationController, […]
I’ve just found that passing an NSManagedObjectContext object via a segue in iOS 5 doesn’t work: the property remains empty. In iOS 6 on the other hand this isn’t a problem: the context arrives just like any other property would, and as logic would dictate. Here’s code from an amended Utility Template app: – (void)prepareForSegue:(UIStoryboardSegue […]
Sometimes you find yourself having a reference to an object (say a View Controller), but you don’t know what class it belongs to. Thankfully there’s a method for this which will work with any NSObject: if ([self.navController isMemberOfClass:[UIViewController class]]) { self.previousTitle = @”Novels”; } In this example we’re testing if our self.navController is a UIViewController. […]
I keep forgetting how to do this… don’t ask me why, it’s not that difficult! So here’s how we define one: – (void)methodName:(NSString *)parameterOne methodNameContinues:(NSString *)parameterTwo; Add more parameters as you please. In theory, the method name is split across these multiple descriptive parts before each parameter is defined. However in reality I find it […]
On the iOS simulator we have the luxury of peeking inside our virtual devices with the Finder. We can do this by heading over to the Finder, holding down Option and clicking Go. This will bring up the Library, in which you can navigate to Application Support / iPhone Simulator / 7.0 / Applications / […]
If you’re displaying images from the main iOS bundle, things are fairly straightforward: self.imageView.image = [UIImage imageNamed:@”Amy.png”]; But if you have an NSURL to your image then it’s not as easy. It took me some digging to find out that you have to convert the URL into NSData first, and then display the data: NSData […]
