Tagged Questions

152
votes
10answers
73k views

Passing Data between View Controllers

I'm new to iOS and Objective-C and the whole MVC paradigm and I'm stuck with the following. I have a View that acts as a data entry form and I want to give the user the option to select multiple ...
466
votes
19answers
170k views

How to check for an active Internet Connection on iPhone SDK?

I would like to check to see if I have an Internet connection on the iPhone using the Cocoa Touch libraries. I came up with a way to do this using an NSURL. The way I did it seems a bit unreliable ...
123
votes
9answers
83k views

How do I do base64 encoding on iphone-sdk?

I'd like to do base64 encoding and decoding, but I could not find any support from the iPhone SDK. How can I do base64 encoding and decoding with or without a library?
228
votes
5answers
125k views

How do I create delegates in Objective-C?

I know how delegates work, and I know how I can use them. But how do I create them?
290
votes
33answers
144k views

How to make a UITextField move up when keyboard is present

With the iPhone SDK: I have a UIView with UITextFields that brings up a keyboard. I need it to be able to: Allow scrolling of the contents of the UIScrollView to see the other text fields once the ...
53
votes
8answers
77k views

iPhone/iOS JSON parsing tutorial

As a learning experience, I want to make an iphone application that calls a webserver/webservice, retrieves a JSON response, and uses that response to populate the rows of a UITableView (assuming it ...
97
votes
10answers
41k views

How to detect iPhone 5 (widescreen devices)?

I've just upgraded to XCode 4.5 GM and found out that you can now apply the '4" Retina' size to your view controller in the storyboard. Now if I want to create an application that runs on both iPhone ...
154
votes
5answers
87k views

Send and receive messages through NSNotificationCenter in Objective-C? [closed]

I need a simple example program to send and receive a message through NSNotificationCenter in Objective-C ?
160
votes
28answers
165k views

EXC_BAD_ACCESS signal received

When deploying the application to the device, the program will quit after a few cycles with the following error: Program received signal: "EXC_BAD_ACCESS". The program runs without any issue on the ...
8
votes
3answers
7k views

Synthesized property and variable with underscore prefix: what does this mean? [duplicate]

Possible Duplicate: Underscore prefix on property name? What does this mean? @synthesize window=_window; I know that in general it means that 'some class' has a window, but why use _window ...
165
votes
11answers
59k views

Best JSON library to use when developing an iPhone application? [closed]

There are a few JSON libraries/frameworks available for Objective-C developers, but I wanted to get the opinion of the resident gurus here on which one is the best, and why. Any thoughts?
108
votes
12answers
86k views

Best book / resources for start learning iOS programming? [closed]

Which resources did you find useful for start learning iOS programming? Books? Website? Videos? Ex: way2ios
20
votes
3answers
3k views

Difference between self.ivar and ivar?

aclass.h @interface aClass : NSObject { NSString *name; } @property (nonatomic, retain) IBOutlet NSString *name; @end aclass.m @implementation aClass @synthesize name; - (void)dealloc { ...
157
votes
38answers
101k views

Applications are expected to have a root view controller at the end of application launch

I get the following error in my console: Applications are expected to have a root view controller at the end of application launch Below is my application:didFinishLaunchWithOptions method: - ...
85
votes
4answers
71k views

iOS: how to perform an HTTP POST request?

I'm approaching iOS development and I'd like to have one of my first applications to perform a HTTP POST request. As far as I can understand, I should manage the connection which handles the request ...

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