It could be that your subView (or one of its parents views) has the userInteractionEnabled
set to false
. UIView has the userInteractionEnabled
set to true
by default, but for example UIImageView (which is a subclass of UIView) has the userInteractionEnabled
set to false
by default.
When set to NO, user events—such as touch and keyboard—intended for
the view are ignored and removed from the event queue. When set to
YES, events are delivered to the view normally. The default value of
this property is YES.
(...)
Note
Some UIKit subclasses override this property and return a different
default value. See the documentation for that class to determine if it
returns a different value.
See Apple docs for more info.
It could be not your subView by itself, but one of its parents views too, because this setting is propagated down.
If set to NO, this view (along with its subviews) is excluded from
receiving touches. Touches on this view or one of its subviews "fall
through" to a view behind it.
source: Programming iOS by Matt Neuburg
For more, check On iOS, if a superview's userInteractionEnabled is NO, then all subviews are disabled as well?