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.

Microbe

possible duplicate of Check if a subview is in a view (importantly, that question already has a Swift answer...) – Placable

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? – Involucel

Answer 1

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.

Microbe

Answer 2

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
        }
    }
}

Shawnshawna

I'm not sure if it's cleaner or not, but it looks like a good alternate method. – Microbe

Answer 3

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

Helton

this actually removes the first view of that type of views, but not that you probably want – Unsnap

Answer 4

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.
}

Menell