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.

How can I change the scroll direction in UICollectionView?

I have a UICollectionView in my storyboard based iOS app. When the device is in the portrait orientation I'd like …

ios objective-c scroll uicollectionview orientation
UICollectionView update a single cell

I am attempting to update a single cell inside a UICollectionView, specifically I am just trying to update an image …

ios objective-c uitableview uicollectionview uicollectionviewcell
Custom UISegmentedControl

How do I make a custom UISegmentedControl? I have 2 images, 1 that should be displayed when the segment is active and …

iphone objective-c cocoa-touch uikit uisegmentedcontrol
Center Align text in UITableViewCell problem

I'm kinda new to Objective-C and iPhone development and I've come across a problem when trying to center the text …

objective-c iphone ios4
Objective-C Runtime: best way to check if class conforms to protocol?

I have a Class (but no instance) and need to know if it conforms to a certain protocol. However, Class …

objective-c runtime
iOS 7 parallax effect in my view controller

I'm developing an app for iOS 7 in Objective-C. I've got a screen in my app with a few buttons and …

ios objective-c swift parallax
Collapse sequences of white space into a single character and trim string

Consider the following example: " Hello this is a long string! " I want to convert that to: "Hello this is a …

objective-c ios nsstring
What is the meaning of id?

I am (trying to) learn Objective-C and I keep coming across a phrase like: -(id) init; And I understand …

objective-c types
Using -performSelector: vs. just calling the method

I'm still kind of new to Objective-C and I'm wondering what is the difference between the following two statements? [object …

objective-c selector dynamic-languages method-dispatch