Objective C: Sending arguments to a method called by a UIButton

Question

I have a method that is being called when a UIButton is clicked. When I create the button I want it to store an NSTimer as an argument.

This is the timer and the cr

Answer 1

I suggest to create a small support class that works like a delegate that simply takes care of the click action for you, then change the target of your addTarget method.

First create your support class:

@interface ClickDelegate : NSObject {
    NSTimer timer;
}

@property (nonatomic, assign) NSTimer *timer;

- (void)clickAction:(id)sender;

@end


@implementation ClickDelegate

@synthesize timer; 

- (void)clickAction:(id)sender {
    // do what you need (like destroy the NSTimer)
}

@end

Then change the target:

// In your view controller
                      
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:(0.009) target:self selector:@selector(moveStickFig:) userInfo:stickFig repeats:YES];                                                                               
   
// Instantiate a new delegate for your delegate action
// and set inside of it all the objects/params you need
ClickDelegate *aDelegate = [[ClickDelegate alloc] init];
aDelegate.timer = timer;

[stickFig addTarget:aDelegate action:@selector(clickAction:) forControlEvents:UIControlEventTouchUpInside];

self.myDelegate = aDelegate; // as suggested in the comments, you need to retain it
[aDelegate release]; // and then release it

In this way you're delegating the click callback to another object. This case is really simple (you just need to get the NSTimer instance) but in a complex scenario it also helps you to design the application logic by delegating different stuff to different small classes.

Hope this helps! Ciao