selector adding parameters - iphone

Question

What I want to do is basically send some form of id with my button so I can calculate which one has been clicked. My buttons get dynamically created and all of them execute the same function that loads a new view, I want to know which button was clicked so I can display the correct data on the new view.
I have an NSMutableArray of annotations that I add a button to the details of the pin. The button works and it loads the next view, but I want to figure out which button was pressed.
I use a singleton with an NSMutableArray called array. The singleton name is Helper
What I did was:
Helper* array = [Helper sharedManager];
int clickedNum = [array.array indexOfObject:annotation];
[myDetailButton setTag:clickedNum];
[myDetailButton addTarget:self action:#selector(moreInfo:event:) forControlEvents:UIControlEventTouchUpInside];
That is where i create the annotations that go unto the map. The next line is my function ID
- (IBAction)moreInfo:(UIButton*)sender
And this is where I want to retrieve the tag
Helper *array = [Helper sharedManager];
array.clicked = sender.tag;
When I run this and click on the button in one of my annotations I get an exception saying NSInvalidArgumentException, reason: -(MapViewController moreInfo:event:]
Any help would be appriciated
Edit:
As requested the interface for helper:
#interface Helper : NSObject {
NSMutableArray *array;
int clicked;
}
#property (nonatomic, retain) NSMutableArray *array;
#property (nonatomic) int clicked;
+(id)sharedManager;
#end
Also I thought it wise to add:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
static NSString *identifier = #"Events";
MKPinAnnotationView *retval = nil;
if ([annotation isKindOfClass:[Events class]])
{
(MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
if (retval == nil) {
retval = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];
Helper *array = [Helper sharedManager];
int clickedNum = [array.array indexOfObject:annotation];
// Set up the Left callout
UIButton *myDetailButton = [UIButton buttonWithType:UIButtonTypeCustom];
myDetailButton.frame = CGRectMake(0, 0, 23, 23);
myDetailButton.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
myDetailButton.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
[myDetailButton setTag:clickedNum];
NSLog([NSString stringWithFormat:#"Testing tag: %#", clickedNum]);
[myDetailButton addTarget:self action:#selector(moreInfo:) forControlEvents:UIControlEventTouchUpInside];
// Set the image for the button
[myDetailButton setImage:[UIImage imageNamed:#"icon72.png"] forState:UIControlStateNormal];
// Set the button as the callout view
retval.leftCalloutAccessoryView = myDetailButton;
}
if (retval) {
[retval setPinColor:MKPinAnnotationColorGreen];
retval.animatesDrop = YES;
retval.canShowCallout = YES;
}
}
return retval;
}

Answer 1

Your method moreInfo: doesn't match what you have set as the selector in
[myDetailButton addTarget:self action:#selector(moreInfo:event:) forControlEvents:UIControlEventTouchUpInside];
So change that to
[myDetailButton addTarget:self action:#selector(moreInfo:) forControlEvents:UIControlEventTouchUpInside];
Or change the method definition.

Answer 2

Although Deepak's answer is correct and will work, since your buttons are annotation callout accessory views, there is an easier way to tell which annotation's button was selected.
Instead of adding your own target+action, use the map view's mapView:annotationView:calloutAccessoryControlTapped: delegate method which will get called when a callout view is tapped. There, the annotation is available as view.annotation. You don't need to set the button tag or use the annotation's index.
For an example, see this other answer.
A separate issue is that in your viewForAnnotation method, you are calling dequeueReusableAnnotationViewWithIdentifier but not doing anything with the result (so not getting any re-use). Instead, it should be assigned to retval and inside the last if, set retval.annotation.