Why doesn't my UIImageView respond to taps?

I have a UIImageView that's being loaded from a NIB. I've hooked up a gesture recognizer to it to开发者_开发知识库 handle taps, but when I run the app, taps aren't being detected.

You need to set the userInteractionEnabled property to YES. It's NO by default. You can either set it in the NIB by checking "User Interaction Enabled" in the Attributes Inspector pane, or set it programmatically after the NIB is loaded by setting the userInteractionEnabled property on the UIImageView.