How to enable user to click the View to hide the kb on iPhone?

I find that the View do not have a touch inside or similar event. So, I make a 开发者_如何学Gobutton on top on the view, and set it Alpha to 0, but after I set to Alpha 0, it cannot touch anymore. Any ideas on this?

You can use UIView subclass and handle touch event there. Methods to look at (defined in UIResponder):

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

If you want to use "invisible" UIButton you should set its type to UIButtonTypeCustom - by default it will appear with no image and title and with transparent background. So technically it will be invisible to user but still be able to respond to all events.