Problems with UILabel Constraints TopAnchor

Question

Chris0309 OP

Created Mar ’21

Replies 3

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Views 2.9k

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Hey guys, I wrote a function which creates an UIView with UIImageView and some Label in it.
This is my Code:

Code Block func setUpInserateWindows(images: [UIImage], priceText: String, descriptionText: String, streetAddress: String, cityAddress: String) {
        var inserates = [UIView]()
        
        for image in images {
            
            let inserateView = UIView()
            let imageView = UIImageView()
            let price = UILabel()
            let description = UILabel()
            let address = UILabel()
            let city = UILabel()
            
            inserateView.addSubview(imageView)
            inserateView.addSubview(price)
            inserateView.addSubview(description)
            
            //InserateView
            inserateView.sizeToFit()
            inserateView.backgroundColor = .clear
            inserateView.translatesAutoresizingMaskIntoConstraints = false
            inserateView.widthAnchor.constraint(equalToConstant: 190).isActive = true
            inserateView.heightAnchor.constraint(equalToConstant: 100).isActive = true
            
            //ImageView
            imageView.backgroundColor = .systemBlue
            imageView.image = image
            imageView.contentMode = .scaleAspectFill
            imageView.layer.cornerRadius = 20
            imageView.layer.masksToBounds = true
            
            imageView.translatesAutoresizingMaskIntoConstraints = false
            imageView.centerXAnchor.constraint(equalTo: inserateView.centerXAnchor).isActive = true
            imageView.topAnchor.constraint(equalTo: inserateView.topAnchor, constant: 5).isActive = true
            imageView.widthAnchor.constraint(equalToConstant: 260).isActive = true
            imageView.heightAnchor.constraint(equalToConstant: 130).isActive = true
            
            //Pricetag
            price.text = priceText
            price.textAlignment = .left
            price.textColor = .black
            price.font = UIFont.boldSystemFont(ofSize: 20)
            
            price.translatesAutoresizingMaskIntoConstraints = false
            price.topAnchor.constraint(equalTo: imageView.bottomAnchor, constant: 5).isActive = true
            price.leadingAnchor.constraint(equalTo: imageView.leadingAnchor).isActive = true
            price.widthAnchor.constraint(equalToConstant: 150).isActive = true
            price.heightAnchor.constraint(equalToConstant: 30).isActive = true
            
            //Description
            description.text = descriptionText
            description.numberOfLines = 1
            description.textColor = .systemGray
            description.textAlignment = .left
            description.font = UIFont.boldSystemFont(ofSize: 15)
            
            description.translatesAutoresizingMaskIntoConstraints = false
            description.topAnchor.constraint(equalTo: price.bottomAnchor).isActive = true
            description.leadingAnchor.constraint(equalTo: imageView.leadingAnchor).isActive = true
            description.widthAnchor.constraint(equalToConstant: 250).isActive = true
            description.heightAnchor.constraint(equalToConstant: 20).isActive = true
            
            //Street Address
            address.text = streetAddress
            address.numberOfLines = 1
            address.textColor = .systemGray
            address.textAlignment = .left
            address.font = UIFont.boldSystemFont(ofSize: 15)
            
            address.translatesAutoresizingMaskIntoConstraints = false
            address.topAnchor.constraint(equalTo: description.bottomAnchor).isActive = true
            address.leadingAnchor.constraint(equalTo: imageView.leadingAnchor).isActive = true
            address.widthAnchor.constraint(equalToConstant: 250).isActive = true
            address.heightAnchor.constraint(equalToConstant: 20).isActive = true
            
            
            inserates.append(inserateView)
        }
        
        for inserate in inserates {
            stackView.addArrangedSubview(inserate)
        }
        
    }

The problem is at the topAnchor of the address Label, it throws me this error: "Thread 1: "Unable to activate constraint with anchors <NSLayoutYAxisAnchor:0x60000344ea40 \"UILabel:0x7f9198d6e830.top\"> and <NSLayoutYAxisAnchor:0x60000344e7c0 \"UILabel:0x7f9198d6e5c0.bottom\"> because they have no common ancestor. Does the constraint or its anchors reference items in different view hierarchies? That's illegal.""

I really do not understand where the problem is, can somebody help me? :)

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Answer 1

Claude31 OP

Mar ’21

Looks like you forgot to addSubview. Add the following at line 16:

Code Block             inserateView.addSubview(address)

Code Block func setUpInserateWindows(images: [UIImage], priceText: String, descriptionText: String, streetAddress: String, cityAddress: String) {
        var inserates = [UIView]()
        
        for image in images {
            let inserateView = UIView()
            let imageView = UIImageView()
            let price = UILabel()
            let description = UILabel()
            let address = UILabel()
            let city = UILabel()
           
            inserateView.addSubview(imageView)
            inserateView.addSubview(price)
            inserateView.addSubview(description)

Note: when you paste code, please avoid all the extra empty lines which makes it more difficult to read. Use Paste and match style for pasting.

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Answer 2

Chris0309 OP

Mar ’21

Ohh wow okay thank's. Maybe I was a bit too tired last evening for seeing this .... :D

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Answer 3

Claude31 OP

Mar ’21

If that's OK, don't forget to close the thread by marking the correct answer.

And then, have some rest 😀

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