How do I associate events with an image view?

Question

Hello

I have an app with an image view. When the user clicks on this view I want to run some code which will change the colour of a label and then hide this view

I have everything setup in the interface, i.e. Outlets etc, but I dont see any events available to associate

Can anyone help or point me in the direction of a good tutorial asap please?

Cheers

Paul

Answer 1

You shouldn't use an image view for this, you should use a UIButton. ImageViews are designed primarily to display, not allow for interaction (which is why their userInteractionEnabled flag is OFF by default.)

Answer 2

Take a look at the documentation for UIResponder - all UIViews, including UIImageView, inherit from it. In turn, UIResponder defines a set of methods you can override to handle the kind of event you're looking at. Start by subclassing UIImageView (call it MyImageView), then override the touchesEnded:withEvent: method.

As Ben Gottlieb said, however, this may be kind of an abuse of the UIKit framework - just make sure the user interaction you're creating makes sense and conforms to good UI practices.

Answer 3

ok thanks for this I will use a button with an image instead

Answer 4

The last time I needed to do this I just used a button also. You can always set up the highlighted state so that it doesn't highlight when someone taps on it if that's what you're trying to avoid.

Note that the higher level UI "actions" are implemented in UIControl, so if all you need to do is track actions like "Touch Up Inside" then it's possible to avoid the event layer, create a UIView in Interface Builder, then change the class to UIControl. You should then be able to use the connections inspector and connect any of those control actions to whatever.

If you place views inside the UIControl and the subviews have "User Interaction Enabled" unchecked (that is, user interaction is disabled) then taps and such inside the UIControl just ignore those and fall through to the UIControl. So another way to do this if you needed to for some reason would be to create a UIView, change the class to UIControl, then place one or more UIImageViews, UILabels, or whatever you want in your generic UIControl view. You can then get actions from the generic UIControl as if all that stuff wasn't inside it.