Top "Objective-c" questions

UITapGestureRecognizer - make it work on touch down, not touch up?

What I'm using the tap event for is very time-sensitive, so I'm curious if it's possible to make UITapGestureRecognizer activate …

ios objective-c swift uitapgesturerecognizer

iPhone SDK: what is the difference between loadView and viewDidLoad?

When working with views and view controllers in an iPhone app, can anyone explain the difference between loadView and viewDidLoad? …

ios objective-c iphone uiview

Why can't I call the default super.init() on UIViewController in Swift?

I am not using a UIViewController from a storyboard and I want to have a custom init function where I …

ios objective-c uiviewcontroller swift ios8

Get selected row in UIPickerView for each component

I have an UIPickerView with 3 components populated with 2 NSMutableArrays (2 components have the same array). A tutorial says: //PickerViewController.m - (…

iphone objective-c cocoa-touch uipickerview

Overriding methods using categories in Objective-C

Can I use a class category to override a method that is already implemented using a category? Like this: 1) Original …

objective-c categories

What gets called when a UISlider value changes?

Does a method get called when a UISlider's value changes? I want to be able to update a value based …

objective-c uislider

dispatch_get_global_queue vs dispatch_get_main_queue

Starting to learn about core data and dispatch_async. There is a block of code to get url of image …

objective-c ios grand-central-dispatch

Single line if statement in Swift

How would one convert the following to Swift from Objective-C? if (myVar) return; Swift does not use parentheses around the …

ios objective-c swift swift3 swift4

Get the current view controller from the app delegate

i am new to ios. I need to know the current view controller from app delegate.. i have no idea …

ios objective-c delegates appdelegate

How to turn the iPhone camera flash on/off?

How can I turn the iPhone's LED camera flash on/off programatically?

ios objective-c iphone ios-camera