Is there any way of asking an iOS view which of its children has first responder status?

In Mac OS X, you can find the first responder like this:

[[self window] firstResponder]

Is there any way of doing it in iOS? Or do you need to enumerate the child controls and send an isFirstRespondermessage to each one?

You would need to iterate over all of the child controls and test the isFirstResponder property. When you encounter TRUE, break out of the loop.

UIView *firstResponder;
for (UIView *view in self.view.subviews) //: caused error
{
    if (view.isFirstResponder)
    {
        firstResponder = view;
        break;
    }
}

BETTER SOLUTION

See Jakob's answer.