Get size of subviews or/and UI elements through code

Question

Luise_2020 OP

Created Apr ’21

Replies 6

Boosts 0

Views 1.4k

Participants 3

I have an App which works with stack Views, to create a good looking UI. To make the App even prettier I want to add color gradient for table view cells and other elements which have a fixed size, this is not a problem. For subviews which change the size depending on the device and orientation it is.

Code Block let topLayer = CAGradientLayer()        topLayer.frame = CGRect(x: 0, y: 0, width: 9000, height: 70)
        topLayer.colors = [UIColor(red: 0.13, green: 0.22, blue: 0.35, alpha: 0.80).cgColor , UIColor(red: 0.18, green: 0.26, blue: 0.39, alpha: 1.00).cgColor]
        topLayer.locations = [0.0, 1.0]
        topView.layer.insertSublayer(topLayer, at: 0)

This is how I create the gradient color. How can get the CGRect Values of a subview or is there another way to gradient color without using the frame of CAGradientLayer ?

Answered by OOPer in 673129022

Have you tried doing it in viewDidLayoutSubviews()?

Code Block     override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        //...
    }

By the way, your code does not seem to have anything to do with SwiftUI. You should use the tag UIKit instead of SwiftUI.

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Answer 1

Claude31 OP

Apr ’21

How can get the CGRect Values of a subview

I probably miss something.

If you get the subView.frame, then you'll have its size, isn't it ?

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Answer 2

Luise_2020 OP

May ’21

Yes that should happen, but if I set the topLayer.frame = topView.frame the layer is not shown correctly. Depending which device I choose in the simulator the layer is either shown too big or too small. I am looking for a solution, where the layer is always as big as the view. In my example the topView is a view where a button and a caption is placed. Depending on the device the height and width are changing, so I want that the size of the layer is changing too. I hope my problem is understandable.

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Answer 3

Claude31 OP

May ’21

No, not very clear.

Should show full code instead.

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Answer 4

Luise_2020 OP

May ’21

Code Block // Outlets
@IBOutlet weak var topView: UIStackView!
//view did load
 override func viewDidLoad() {
        super.viewDidLoad()
        let topLayer = CAGradientLayer()
        topLayer.frame = topView.frame
        topLayer.colors = [UIColor(red: 0.13, green: 0.22, blue: 0.35, alpha: 0.80).cgColor , UIColor(red: 0.18, green: 0.26, blue: 0.39, alpha: 1.00).cgColor]
        topLayer.locations = [0.0, 1.0]
        topView.layer.insertSublayer(topLayer, at: 0)
}

If I use this code and run it on the simulator the layer is not as big as the view. Unfortunately I can not attach a picture to show you how it looks. I want the layer always as big as the view.
Maybe it is clearer now ?

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Answer 5

OOPer OP

May ’21

Accepted Answer

Have you tried doing it in viewDidLayoutSubviews()?

Code Block     override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        //...
    }

By the way, your code does not seem to have anything to do with SwiftUI. You should use the tag UIKit instead of SwiftUI.

1

Answer 6

Luise_2020 OP

May ’21

Thank you, it worked and you are right, I am using UIKit, sorry for that mistake

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