Check if a subview is in a view using Swift

Question

How do I test if a subview has already been added to a parent view? If it hasn't been added, I want to add it. Otherwise, I want to remove it.

possible duplicate of [Check if a subview is in a view](http://stackoverflow.com/questions/7421298/check-if-a-subview-is-in-a-view) (importantly, that question already has a Swift answer...) — nhgrif, Jun 19 '15 at 12:21
In response to nhgrif's comment, the answer you linked to (an Obj-C question) was edited (by YOU) the same day you posted the comment. Did it have Swift at 11:45am when this question was posted and was it an adequate answer? If so, why'd you update it? — Dave G, Feb 18 '17 at 17:24

score 88 · Accepted Answer · edited Feb 04 '21 at 09:53

88

You can use the UIView method isDescendantOfView:

if mySubview.isDescendant(of: someParentView) {
    mySubview.removeFromSuperview()
} else {
    someParentView.addSubview(mySubview)
}

You may also need to surround everything with if mySubview != nil depending on your implementation.

edited Feb 04 '21 at 09:53

Zaporozhchenko Oleksandr

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answered Jun 19 '15 at 11:45

Suragch

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score 26 · Answer 2 · edited Dec 25 '16 at 04:29

26

This is a much cleaner way to do it:

if myView != nil { // Make sure the view exists

        if self.view.subviews.contains(myView) {
            self.myView.removeFromSuperview() // Remove it
        } else {
           // Do Nothing
        }
    }
}

edited Dec 25 '16 at 04:29

Suragch

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answered Dec 24 '16 at 19:00

Ryan Cocuzzo

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I'm not sure if it's cleaner or not, but it looks like a good alternate method. – Suragch Dec 25 '16 at 04:30

score 11 · Answer 3 · answered May 17 '19 at 03:41

11

for view in self.view.subviews {
    if let subView = view as? YourNameView {
        subView.removeFromSuperview()
        break
    }
}

answered May 17 '19 at 03:41

Giang

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this actually removes the first view of that type of views, but not that you probably want – Zaporozhchenko Oleksandr Feb 04 '21 at 09:52

score 7 · Answer 4 · answered May 17 '19 at 05:12

Here we used two different views. Parent view is the view in which we are searching for descendant view and check wether added to parent view or not.

if parentView.subviews.contains(descendantView) {
   // descendant view added to the parent view.
  }else{
   // descendant view not added to the parent view.
}

Check if a subview is in a view using Swift

4 Answers4