Top "Objective-c" questions

This tag should be used only on questions that are about Objective-C features or depend on code in the language.

Why NSUserDefaults failed to save NSMutableDictionary in iOS?

I'd like to save an NSMutableDictionary object in NSUserDefaults. The key type in NSMutableDictionary is NSString, the value type is …

ios objective-c cocoa-touch nsuserdefaults nscoding
How to change the device orientation programmatically in iOS 6

In iOS 5 we could change the device orientation programmatically like so: [[UIDevice currentDevice] setOrientation:UIInterfaceOrientationLandscapeRight]; But in iOS 6 setOrientation is …

ios objective-c uiinterfaceorientation
Why does Apple recommend to use dispatch_once for implementing the singleton pattern under ARC?

What's the exact reason for using dispatch_once in the shared instance accessor of a singleton under ARC? + (MyClass *)sharedInstance { // …

ios objective-c singleton automatic-ref-counting
iOS SDK - Programmatically generate a PDF file

Using the CoreGraphics framework is tedious work, in my honest opinion, when it comes to programmatically drawing a PDF file. …

iphone objective-c ipad ios pdf-generation
How shouldChangeCharactersInRange works in Swift?

I'm using shouldChangeCharactersInRange as a way of using on-the-fly type search. However I'm having a problem, shouldChangeCharactersInRange gets called before …

ios objective-c swift uitextfielddelegate nsrange
Understanding performSegueWithIdentifier

Can someone more knowledgeable than I explain performSegueWithIdentifier:sender: for me? I need to switch views (and classes) and also …

ios objective-c xcode uikit segue
iphone Core Data Unresolved error while saving

I am getting a strange error message from the core data when trying to save but the problem that the …

iphone objective-c ios core-data
Closing a view displayed via a modal segue

I'm manually invoking a segue (set as modal) in order to display a login form in Xcode 4.2 using Storyboards with …

objective-c ios cocoa-touch uistoryboard
What is Objective C++?

What is Objective C++ and can I use this language in Xcode?

c++ objective-c xcode objective-c++
afnetworking 3.0 Migration: how to POST with headers and HTTP Body

I am trying to make a POST request which has HTTPHeader Fields and a HTTP body to the youtube API. …

ios objective-c post afnetworking afnetworking-3