UIButton TouchUpInside Touch Location

问题:

So I have a large UIButton, it is a UIButtonTypeCustom, and the button target is called for UIControlEventTouchUpInside. My question is how can I determine where in the UIButton the touch occured. I want this info so I can display a popup from the touch location. Here is what I've tried:

UITouch *theTouch = [touches anyObject];
CGPoint where = [theTouch locationInView:self];
NSLog(@" touch at (%3.2f, %3.2f)", where.x, where.y);

and various other iterations. The button's target method get info from it via the sender:

    UIButton *button = sender;

So is there any way I could use something like: button.touchUpLocation?

I looked online and couldn't find anything similar to this so thanks in advance.

回答1:

UITouch *theTouch = [touches anyObject];
CGPoint where = [theTouch locationInView:self];
NSLog(@" touch at (%3.2f, %3.2f)", where.x, where.y);

That's the right idea, except that this code is probably inside an action in your view controller, right? If so, then self refers to the view controller and not the button. You should be passing a pointer to the button into -locationInView:.

Here's a tested action that you can try in your view controller:

- (IBAction)buttonPressed:(id)sender forEvent:(UIEvent*)event
{
    UIView *button = (UIView *)sender;
    UITouch *touch = [[event touchesForView:button] anyObject];
    CGPoint location = [touch locationInView:button];
    NSLog(@"Location in button: %f, %f", location.x, location.y);
}

回答2:

For Swift 3.0:

@IBAction func buyTap(_ sender: Any, forEvent event: UIEvent) 
{
       let myButton:UIButton = sender as! UIButton
       let touches: Set<UITouch>? = event.touches(for: myButton)
       let touch: UITouch? = touches?.first
       let touchPoint: CGPoint? = touch?.location(in: myButton)
       print("touchPoint\(touchPoint)")  
}