How to add a touch event to a UIView?

Manni picture Manni · Jan 11, 2011 · Viewed 339.5k times · Source

How do I add a touch event to a UIView?
I try:

UIView *headerView = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.size.width, nextY)] autorelease];
[headerView addTarget:self action:@selector(myEvent:) forControlEvents:UIControlEventTouchDown];
// ERROR MESSAGE: UIView may not respond to '-addTarget:action:forControlEvents:'

I don't want to create a subclass and overwrite

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

Answer

Nathan Eror picture Nathan Eror · Jan 11, 2011

In iOS 3.2 and higher, you can use gesture recognizers. For example, this is how you would handle a tap event:

//The setup code (in viewDidLoad in your view controller)
UITapGestureRecognizer *singleFingerTap = 
  [[UITapGestureRecognizer alloc] initWithTarget:self 
                                          action:@selector(handleSingleTap:)];
[self.view addGestureRecognizer:singleFingerTap];

//The event handling method
- (void)handleSingleTap:(UITapGestureRecognizer *)recognizer
{
  CGPoint location = [recognizer locationInView:[recognizer.view superview]];

  //Do stuff here...
}

There are a bunch of built in gestures as well. Check out the docs for iOS event handling and UIGestureRecognizer. I also have a bunch of sample code up on github that might help.