How to send an object as argument when a UIButton is tapped?

Question

I have the following code inside my UIViewController -

[flipButton addTarget:self.navigationController.delegate action:@selector(changeModeAction:) forControlEvents:UIControlEventTouchUpInside];

As you can see, it calls a method inside it's navigation controller delegate. How do I correctly pass along an object to this method?

score 11 · Answer 1 · edited Jun 22 '12 at 12:13

You can use the layer property. Add the object you want to pass as the value in the layer dictionary.

[[btn layer] setValue:yourObj forKey:@"yourKey"];

This yourObj is accessible from the button action function:

-(void)btnClicked:(id)sender
{
    yourObj = [[sender layer] valueForKey:@"yourKey"];
}

With this method you can pass multiple values to the button function just by adding new objects in the dictionary with different keys.

score 2 · Accepted Answer · answered Mar 22 '11 at 20:32

2

Or you can use objc_setAssociatedObject and objc_getAssociatedObject

answered Mar 22 '11 at 20:32

Henning

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Is this documented or private API bound to get rejected by Apple? – skålfyfan Mar 22 '11 at 21:21
Look in the documentation. Try "Objective-C Runtime Reference". – Henning Mar 24 '11 at 14:46
Could You please explain by or sample code or any link,that would be really helpful.Thanks – Sanoj Kashyap May 23 '13 at 06:39

score 1 · Answer 3 · edited May 23 '17 at 12:00

1

When changeModeAction: is called flipButton should pass itself as the sender. If you need additional parameters passed you could create a category for the type of flipButton to store additional information or you could set up a dictionary that the navigationController can access e.g.

if(sender == flipButton)
 id obj = [someDictionary objectForKey:@"flipButtonKey"];

edited May 23 '17 at 12:00

Community

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1

answered Mar 22 '11 at 20:18

Joe

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score 0 · Answer 4 · answered Mar 16 '17 at 05:16

extension + Swift 3.0

extension NSObject {

fileprivate struct ObjectTagKeys {
    static var ObjectTag = "ObjectTag"
}

func setObjectTag(_ tag:Any!) {
    objc_setAssociatedObject(self, &ObjectTagKeys.ObjectTag, tag, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}

func getObjectTag() -> Any
{
    return objc_getAssociatedObject(self, &ObjectTagKeys.ObjectTag)
}

}

How to send an object as argument when a UIButton is tapped?

4 Answers4