Questions tagged [ios]
iOS is the mobile operating system running on the Apple iPhone, iPod touch, and iPad. Use this tag [ios] for questions related to programming on the iOS platform. Use the related tags [objective-c] and [swift] for issues specific to those programming languages.
74,437
questions
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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 ...
- 34.6k
1322
votes
82
answers
1.0m
views
Xcode - How to fix 'NSUnknownKeyException', Reason: "… this class is not key value coding-compliant for the key X" error?
I'm trying to link a UILabel with an IBOutlet created in my class.
My application is crashing with the following error"
***
Terminating app due to uncaught exception
'NSUnknownKeyException', ...
113
votes
13
answers
89k
views
Returning data from async call in Swift function
I have created a utility class in my Swift project that handles all the REST requests and responses. I have built a simple REST API so I can test my code. I have created a class method that needs to ...
- 3,093
1614
votes
29
answers
708k
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Using Auto Layout in UITableView for dynamic cell layouts & variable row heights
How do you use Auto Layout within UITableViewCells in a table view to let each cell's content and subviews determine the row height (itself/automatically), while maintaining smooth scrolling ...
- 30.4k
111
votes
1
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Speed up fetching posts for my social network app by using query instead of observing a single event repeatedly
I have an array of keys which lead to post objects for my social network like so /posts/id/(post info)
When I load the posts I load /posts/0 and then /posts/1 etc using the observeSingleEventOfType(....
- 3,014
1601
votes
30
answers
959k
views
Transport security has blocked a cleartext HTTP
What setting do I need to put in my info.plist to enable HTTP mode as per the following error message?
Transport security has blocked a cleartext HTTP (http://) resource
load since it is insecure....
- 27.1k
606
votes
6
answers
240k
views
What are Unwind segues for and how do you use them?
iOS 6 and Xcode 4.5 has a new feature referred to as "Unwind Segue":
Unwind segues can allow transitioning to existing instances of scenes in a storyboard
In addition to this brief entry in Xcode ...
- 22.1k
1792
votes
99
answers
652k
views
How can I make a UITextField move up when the keyboard is present - on starting to edit?
With the iOS SDK:
I have a UIView with UITextFields that bring 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 ...
1406
votes
39
answers
512k
views
How can I check for an active Internet connection on iOS or macOS?
I would like to check to see if I have an Internet connection on iOS using the Cocoa Touch libraries or on macOS using the Cocoa libraries.
I came up with a way to do this using an NSURL. The way I ...
- 46.9k
1325
votes
27
answers
486k
views
How do I sort an NSMutableArray with custom objects in it?
What I want to do seems pretty simple, but I can't find any answers on the web. I have an NSMutableArray of objects, and let's say they are 'Person' objects. I want to sort the NSMutableArray by ...
- 45k
774
votes
20
answers
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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?
- 15.2k
521
votes
39
answers
751k
views
Loading/Downloading image from URL on Swift
I'd like to load an image from a URL in my application, so I first tried with Objective-C and it worked, however, with Swift, I've a compilation error:
'imageWithData' is unavailable: use object ...
- 5,297
448
votes
26
answers
252k
views
Symbolicating iPhone App Crash Reports
I'm looking to try and symbolicate my iPhone app's crash reports.
I retrieved the crash reports from iTunes Connect. I have the application binary that I submitted to the App Store and I have the ...
- 58.4k
504
votes
30
answers
150k
views
How to develop or migrate apps for iPhone 5 screen resolution?
The new iPhone 5 display has a new aspect ratio and a new resolution (640 x 1136 pixels).
What is required to develop new or transition already existing applications to the new screen size?
What ...
- 19.9k
174
votes
4
answers
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views
What is the best way to deal with the NSDateFormatter locale "feature"?
It seems that NSDateFormatter has a "feature" that bites you unexpectedly: If you do a simple "fixed" format operation such as:
NSDateFormatter* fmt = [[NSDateFormatter alloc] ...
- 47.3k
52
votes
3
answers
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views
How to add Exception Breakpoint in Xcode?
How to add Exception Breakpoint in Xcode?
int main(int argc, char *argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
int retVal = UIApplicationMain(argc, argv, nil, @"...
- 668
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votes
42
answers
1.1m
views
How can I develop for iPhone using a Windows development machine?
Is there any way to tinker with the iPhone SDK on a Windows machine? Are there plans for an iPhone SDK version for Windows?
The only other way I can think of doing this is to run a Mac VM image on a ...
511
votes
31
answers
166k
views
UIDevice uniqueIdentifier deprecated - What to do now?
It has just come to light that the UIDevice uniqueIdentifier property is deprecated in iOS 5 and unavailable in iOS 7 and above. No alternative method or property appears to be available or ...
- 20.1k
468
votes
8
answers
446k
views
How do I load an HTTP URL with App Transport Security enabled in iOS 9? [duplicate]
So, the new beta SDK of iOS released last night has "App Transport Security" which encourages developers to use https instead of http. In principle, this is a great idea, and I already use https in ...
- 5,108
1947
votes
28
answers
534k
views
What's the difference between the atomic and nonatomic attributes?
What do atomic and nonatomic mean in property declarations?
@property(nonatomic, retain) UITextField *userName;
@property(atomic, retain) UITextField *userName;
@property(retain) UITextField *...
- 183k
422
votes
12
answers
101k
views
How dangerous is it to compare floating point values?
I know UIKit uses CGFloat because of the resolution independent coordinate system.
But every time I want to check if for example frame.origin.x is 0 it makes me feel sick:
if (theView.frame.origin.x ...
- 40.3k
390
votes
21
answers
361k
views
Swift - encode URL
If I encode a string like this:
var escapedString = originalString.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)
it doesn't escape the slashes /.
I've searched and found this ...
- 5,107
909
votes
36
answers
531k
views
How to check iOS version?
I want to check if the iOS version of the device is greater than 3.1.3
I tried things like:
[[UIDevice currentDevice].systemVersion floatValue]
but it does not work, I just want a:
if (version > ...
- 9,109
792
votes
32
answers
241k
views
Can I embed a custom font in an iPhone application?
I would like to have an app include a custom font for rendering text, load it, and then use it with standard UIKit elements like UILabel. Is this possible?
- 32.5k
330
votes
5
answers
133k
views
How do I associate file types with an iPhone application?
On the subject of associating your iPhone app with file types.
In this informative question I learned that apps could be associated with custom URL protocols.
That was almost one year ago and since ...
- 11.3k
649
votes
28
answers
345k
views
Presenting modal in iOS 13 fullscreen
In iOS 13 there is a new behaviour for modal view controller when being presented.
Now it's not fullscreen by default and when I try to slide down, the app just dismiss the View Controller ...
- 16.4k
274
votes
28
answers
161k
views
How to force NSLocalizedString to use a specific language
On iPhone NSLocalizedString returns the string in the language of the iPhone.
Is it possible to force NSLocalizedString to use a specific language to have the app
in a different language than the ...
- 3,691
550
votes
32
answers
411k
views
How to determine the current iPhone/device model?
Is there a way to get the device model name (iPhone 4S, iPhone 5, iPhone 5S, etc) in Swift?
I know there is a property named UIDevice.currentDevice().model but it only returns device type (iPod touch,...
- 6,863
360
votes
10
answers
357k
views
How to pass prepareForSegue: an object
I have many annotations in a mapview (with rightCalloutAccessory buttons). The button will perform a segue from this mapview to a tableview. I want to pass the tableview a different object (that ...
- 4,142
376
votes
31
answers
199k
views
Determine device (iPhone, iPod Touch) with iOS
Is there a way to determine the device running an application. I want to distinguish between iPhone and iPod Touch, if possible.
- 5,588
434
votes
11
answers
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views
Test iOS app on device without apple developer program or jailbreak
How can I test an iOS application on my iPod Touch without registering for the Apple Developer Program or jailbreaking my iPod?
Neither is a viable option at the moment.
I'd like to test on the ...
- 18.2k
104
votes
9
answers
97k
views
How can I debug 'unrecognized selector sent to instance' error
I am creating a custom table cell view for my table view. After I connect an image view of custom cell (in storyboard) to my code in swift, I get the following error.
[UITableViewCellContentView ...
- 20k
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votes
61
answers
672k
views
How to change Status Bar text color in iOS
My application has a dark background, but in iOS 7 the status bar became transparent. So I can't see anything there, only the green battery indicator in the corner. How can I change the status bar ...
339
votes
9
answers
236k
views
Programmatically get own phone number in iOS
Is there any way to get own phone number by standard APIs from iPhone SDK?
- 9,463
275
votes
7
answers
143k
views
How to store custom objects in NSUserDefaults
Alright, so I've been doing some poking around, and I realize my problem, but I don't know how to fix it. I have made a custom class to hold some data. I make objects for this class, and I need to ...
- 9,537
442
votes
33
answers
381k
views
The simplest way to resize an UIImage?
In my iPhone app, I take a picture with the camera, then I want to resize it to 290*390 pixels. I was using this method to resize the image :
UIImage *newImage = [image _imageScaledToSize:...
- 5,906
321
votes
40
answers
390k
views
Undefined symbols for architecture armv7
This problem has been driving me crazy, and I can't work out how to fix it...
Undefined symbols for architecture armv7:
"_deflateEnd", referenced from:
-[ASIDataCompressor closeStream] in ...
- 4,596
565
votes
41
answers
431k
views
How do I size a UITextView to its content?
Is there a good way to adjust the size of a UITextView to conform to its content? Say for instance I have a UITextView that contains one line of text:
"Hello world"
I then add another line of text:
...
- 10.1k
119
votes
20
answers
162k
views
How to get the indexpath.row when an element is activated?
I have a tableview with buttons and I want to use the indexpath.row when one of them is tapped.
This is what I currently have, but it always is 0
var point = Int()
func buttonPressed(sender: ...
- 1,645
236
votes
19
answers
137k
views
How do I do base64 encoding on iOS?
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?
- 9,775
228
votes
0
answers
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iPhone development on Windows [duplicate]
Possible Duplicate:
How can I develop for iPhone using a Windows development machine?
Is there a way to develop iPhone (iOS) applications on Windows? I really don't want to get yet another ...
329
votes
11
answers
269k
views
Looking to understand the iOS UIViewController lifecycle
Could you explain me the correct manner to manage the UIViewController lifecycle?
In particular, I would like to know how to use Initialize, ViewDidLoad, ViewWillAppear, ViewDidAppear, ...
- 33.4k
633
votes
6
answers
415k
views
Send and receive messages through NSNotificationCenter in Objective-C?
I am attempting to send and receive messages through NSNotificationCenter in Objective-C. However, I haven't been able to find any examples on how to do this. How do you send and receive messages ...
Cathy
1048
votes
14
answers
447k
views
Constants in Objective-C
I'm developing a Cocoa application, and I'm using constant NSStrings as ways to store key names for my preferences.
I understand this is a good idea because it allows easy changing of keys if ...
- 20.4k
568
votes
19
answers
692k
views
How to add constraints programmatically using Swift
I'm trying to figure this out since last week without going any step further. Ok, so I need to apply some constraints programmatically in Swift to a UIView using this code:
var new_view:UIView! = ...
- 6,251
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votes
28
answers
816k
views
How to link to apps on the app store
I am creating a free version of my iPhone game. I want to have a button inside the free version that takes people to the paid version in the app store. If I use a standard link
http://itunes.apple....
2340
votes
51
answers
764k
views
Vertically align text to top within a UILabel
I have a UILabel with space for two lines of text. Sometimes, when the text is too short, this text is displayed in the vertical center of the label.
How do I vertically align the text to always be ...
- 28.9k
1049
votes
12
answers
338k
views
How do I animate constraint changes?
I'm updating an old app with an AdBannerView and when there is no ad, it slides off screen. When there is an ad it slides on the screen. Basic stuff.
Old style, I set the frame in an animation block.
...
- 23.1k
546
votes
18
answers
307k
views
How to programmatically send SMS on the iPhone?
Does anybody know if it's possible, and how, to programmatically send a SMS from the iPhone, with the official SDK / Cocoa Touch?
Marco
232
votes
16
answers
192k
views
Swift extract regex matches
I want to extract substrings from a string that match a regex pattern.
So I'm looking for something like this:
func matchesForRegexInText(regex: String!, text: String!) -> [String] {
???
}
...
- 6,480