自动换行在UILabel中不起作用

Question

Below result, for UILabel . it only happens if the word is too long.

Below is something I want to achieve. It works if I reduce the Lable height. but Label height is dynamic

Help appreciate. Thank you

Answer 1

As I found out all lineBreakMode modes will pass characters on another line when the word is bigger than that line. It seems that the only way to fix it is to change font size to fit this word. Autoshrink has some limitations and does not detect splitting word to several lines, so you need manually detect that word is not fitted and change font size accordingly.

Question with the same problem: How to make multi-line UILabel text fit within predefined width without wrapping mid-word

Answer 2

You can set constraint as your requirement for a label. suppose if you don't want fix height then It's not necessary to set bottom constraint.

See below image I have set a constraint for dynamic label height. Hope this will help you.

Answer 3

Try this. It should shrink the font just enough to fit the longest word on a line. If you see a better way let me know as I would love to improve this.I am sure I could adapt it to work in IB.

import UIKit

extension UILabel{

    func adjustedFont()->UIFont {
        let attributes: [NSAttributedStringKey: Any] = [.font: font]
        let attributedString = NSAttributedString(string: text ?? "", attributes: attributes)
        let drawingContext = NSStringDrawingContext()
        drawingContext.minimumScaleFactor = minimumScaleFactor

        attributedString.boundingRect(with: bounds.integral.size,
                                      options: .usesLineFragmentOrigin,
                                      context: drawingContext)

        let fontSize = font.pointSize * drawingContext.actualScaleFactor

        return font.withSize(fontSize)
    }

    func fitMaxWord(){
        layoutIfNeeded()
        let scaledFont = self.adjustedFont()
        let currentFont = scaledFont
        if let txt = text,
            let maxString = txt.components(separatedBy: " ").max(by: {$1.count > $0.count})?.replacingOccurrences(of: "\n", with: ""){
            let maxFontSize: CGFloat = currentFont.pointSize
            let minFontSize: CGFloat = 5.0


            var q = maxFontSize
            var p = minFontSize
            let height = currentFont.lineHeight
            let constraintSize = CGSize(width: .greatestFiniteMagnitude, height: height)
            var sizedFont = currentFont
            while(p <= q){
                let currentSize = (p + q) / CGFloat(2)
                sizedFont = currentFont.withSize( CGFloat(currentSize) )

                let text = NSMutableAttributedString(string:maxString, attributes:[NSAttributedStringKey.font:sizedFont])

                let textRect = text.boundingRect(with: constraintSize, options: [.usesLineFragmentOrigin], context: nil).integral
                let labelSize = textRect.width

                //1 is a fudge factor
                if labelSize == ceil(self.bounds.width - 1){
                    break
                }else if labelSize > ceil(self.bounds.width - 1){
                    q = currentSize - 0.1
                }else{
                    p = currentSize + 0.1
                }
            }

            if sizedFont.pointSize < currentFont.pointSize{
                self.font = sizedFont
            }
        }
    }
}

Minimum example:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        //we could test longer text
        //
        let text = "CHULALONGKORN UNIVERSITY Plus a lot of additional text to make sure it still does not clip a word"
        let testLabel = UILabel(frame: .zero)
        //testLabel.text = "CHULALONGKORN UNIVERSITY"
        testLabel.text = text
        testLabel.numberOfLines = 0
        testLabel.textAlignment = .center
        testLabel.font = UIFont.systemFont(ofSize: 45)
        testLabel.adjustsFontSizeToFitWidth = true //unneeded in this instance but lets set it
        testLabel.minimumScaleFactor = 0.3
        self.view.addSubview(testLabel)
        testLabel.translatesAutoresizingMaskIntoConstraints = false
        testLabel.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 20).isActive = true
        testLabel.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: -20).isActive = true
        testLabel.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 50).isActive = true
        self.view.layoutIfNeeded()
        testLabel.fitMaxWord()
    }


}

This should work in most circumstances. I tested with your text and more text. You can see both in the example above.

Answer 4

Here is a solution to your problem if, your string has fixed value, as you've shown in your question (ie CHULALONGKORN UNIVERSITY ).

Set following properties for your label in your interface builder.

1. Set your label text value in two lines, as shown in below snapshot (not in a single line like - CHULALONGKORN UNIVERSITY ). Press alt + enter inplace of space between two words.
2. Set number of lines = 2
3. Set line break mode = Truncate Tail
4. Set Autoshrink to Minimum Font Scale' and value for scale to 0.5` or whatever minimum scale you like to set.

-

Answer 5

you should try UILabel alignment justified

Answer 6

whenever you give label height as Dynamic

Select the Lines Count as 0 in Attributes Inspector

Then automatically based on the Content of label the height is increases.