How to duplicate a UIButton in Objective C?

Question

The object inherits from NSObject.

Is there a method to create a copy of it as a new object?

Why are you trying to copy a UIButton? There may be a better path... — Kendall Helmstetter Gelner, Jul 07 '09 at 15:37
Is there a downside to copying a UIButton? I need to dynamically create new buttons based off of an existing one. — James Skidmore, Jul 09 '09 at 17:30
You duplicate a button to make, say, a row of buttons. @JamesSkidmore Here's full code http://stackoverflow.com/a/26438692/294884 — Fattie, Oct 18 '14 at 10:24

score 65 · Accepted Answer · answered Jul 07 '09 at 15:33

65

UIButton does not conform to NSCopying, so you cannot make a copy via -copy.

However, it does conform to NSCoding, so you can archive the current instance, then unarchive a 'copy'.

NSData *archivedData = [NSKeyedArchiver archivedDataWithRootObject: button];
UIButton *buttonCopy = [NSKeyedUnarchiver unarchiveObjectWithData: archivedData];

Afterwards, you'll have to assign any additional properties that weren't carried over in the archive (e.g. the delegate) as necessary.

answered Jul 07 '09 at 15:33

Jim Correia

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Clever! I would've probably just added -copy via a category, but this is better. =) – Dave DeLong Jul 07 '09 at 15:46
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Isn't this a bit slow? – mattsven Aug 02 '13 at 15:22

score 4 · Answer 2 · answered Jul 07 '09 at 15:37

UIButton doesn't conform to the NSCopying protocol, so you have copy it by hand. On the other hand, it is not a bad thing, since it is not exactly clear what does it mean to copy a button. For example, should it add the button copy to the same view the original is in? Should it fire the same methods when tapped?

Joel Teply · Answer 3 · 2014-04-03T19:37:21.410

To add to Jim's answer above using a category

 @implementation UIButton (NSCopying)

 - (id)copyWithZone:(NSZone *)zone {
     NSData *archivedData = [NSKeyedArchiver archivedDataWithRootObject:self];
     UIButton *buttonCopy = [NSKeyedUnarchiver unarchiveObjectWithData: archivedData];
     return buttonCopy;
 }

 @end

if you wanted to copy all of the actions from one button to another, add something like this:

 for (id target in button.allTargets) {
    NSArray *actions = [button actionsForTarget:target forControlEvent:UIControlEventTouchUpInside];
    for (NSString *action in actions) {
        [newButton addTarget:target action:NSSelectorFromString(action) forControlEvents:UIControlEventTouchUpInside];
    }
 }

score 0 · Answer 4 · answered Jul 07 '09 at 15:14

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If it implements the NSCopying protocol, then the -copy method should do the trick.

answered Jul 07 '09 at 15:14

Stephen Darlington

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I'm trying to copy a UIButton. Any ideas? – James Skidmore Jul 07 '09 at 15:15

score 0 · Answer 5 · edited Jul 22 '09 at 15:47

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You can get more information about the -copy method and how it works with sub-objects on the ADC reference site. As Stephen Darlington mentions, you need to implement the NSCopying protocol in your object.

documentation

edited Jul 22 '09 at 15:47

Brad Gilbert

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answered Jul 07 '09 at 15:16

Weegee

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score 0 · Answer 6 · answered Oct 12 '18 at 11:42

0

Swift 3/4 version would be:

let archivedData = NSKeyedArchiver.archivedData(withRootObject: button as Any)
let buttonCopy = NSKeyedUnarchiver.unarchiveObject(with: archivedData) as? UIButton

answered Oct 12 '18 at 11:42

Aron

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How to duplicate a UIButton in Objective C?

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