sendSubviewToBack is not working when an UIView is added to a custom UILabel-CodePudding

I am iterating values and add them to a container UIView.

    for value in bla {
        
        // Create a new label
        let labelHashtag = UILabelBadge()
        labelHashtag.backgroundColor = .white
        labelHashtag.frame.size.width = labelHashtag.intrinsicContentSize.width   tagPadding
        labelHashtag.frame.size.height = tagHeight
        labelHashtag.layer.cornerRadius = labelHashtag.layer.frame.size.height / 2
        labelHashtag.topInset = 2
        labelHashtag.bottomInset = 2
        labelHashtag.rightInset = 6
        labelHashtag.leftInset = 6
        labelHashtag.textAlignment = .center
        
        // !!! Here I am trying to add an UIView and send it back !!!
        let bla = UIView()
        bla.frame = labelHashtag.bounds
        bla.backgroundColor = .red
        labelHashtag.addSubview(bla)
        labelHashtag.sendSubviewToBack(bla)
        
        Container.addSubview(labelHashtag)
        }

It also does not work when I use insertSubview at: 0. It will stay on the top of my UILabel.

How can I add an UIView and send it back?

CodePudding user response：

When you add subview on UILabel means that UILabel is the root and all subviews will on the front of root view.

From your question, there are two approaches to achieve that.

First one, create a root UIView and add your UILabel and UIView into

for value in bla {
    let rootUIView = UIView()
    // Create a new label
    let labelHashtag = UILabelBadge()
    labelHashtag.backgroundColor = .white
    labelHashtag.frame.size.width = labelHashtag.intrinsicContentSize.width   tagPadding
    labelHashtag.frame.size.height = tagHeight
    labelHashtag.layer.cornerRadius = labelHashtag.layer.frame.size.height / 2
    labelHashtag.topInset = 2
    labelHashtag.bottomInset = 2
    labelHashtag.rightInset = 6
    labelHashtag.leftInset = 6
    labelHashtag.textAlignment = .center

    // !!! Here I am trying to add an UIView and send it back !!!
    let backgroundView = UIView()
    backgroundView.frame = labelHashtag.bounds
    backgroundView.backgroundColor = .red

    rootUIView.addSubview(labelHashtag)
    rootUIView.addSubview(backgroundView)
    rootUIView.sendSubviewToBack(backgroundView)

    Container.addSubview(rootUIView)
}

Second one, make your UIView as a root and add your custom UILabel into it

for value in bla {
    // Create a new label
    let labelHashtag = UILabelBadge()
    labelHashtag.backgroundColor = .white
    labelHashtag.frame.size.width = labelHashtag.intrinsicContentSize.width   tagPadding
    labelHashtag.frame.size.height = tagHeight
    labelHashtag.layer.cornerRadius = labelHashtag.layer.frame.size.height / 2
    labelHashtag.topInset = 2
    labelHashtag.bottomInset = 2
    labelHashtag.rightInset = 6
    labelHashtag.leftInset = 6
    labelHashtag.textAlignment = .center

    // !!! Here I am trying to add an UIView and send it back !!!
    let backgroundView = UIView()
    backgroundView.frame = labelHashtag.bounds
    backgroundView.backgroundColor = .red

    backgroundView.addSubview(labelHashtag)
    Container.addSubview(backgroundView)
}