When putting multiline label (with linebreak set to Word Wrap) into a stack view, the label immediately loses the linebreak and displays the label text in one line instead.
Why is this happening and how does one preserve multiline label within a stack view?
The correct answer is here: https://stackoverflow.com/a/43110590/566360
- Embed the
UILabelinside aUIView(Editor -> Embed In -> View)- Use constraints to fit the
UILabelto theUIView(for example, trailing space, top space, and leading space to superview constraints)
- Use constraints to fit the
The UIStackView will stretch out the UIView to fit properly, and the UIView will constrain the UILabel to multiple lines.
For a horizontal stack view that has a UILabel as one of its views, in Interface Builder firstly set label.numberOfLines = 0. This should allow the label to have more than 1 line. This initially failed to work for me when the stack view had stackView.alignment = .fill. To make it work simply set stackView.alignment = .center. The label can now expand to multiple lines within the UIStackView.
The Apple documentation says
For all alignments except the fill alignment, the stack view uses each arranged view’s intrinsicContentSize property when calculating its size perpendicular to the stack’s axis
Note the word except here. When .fill is used the horizontal UIStackView does NOT resize itself vertically using the arranged subviews sizes.
- First set the label number of lines to 0
- The stack view still won't grow to
multiLineunless you give it a fixed width. When we fix its width then it break to multiline when that width is reached as shown:
If we don't give a fixed width to the stack view then things get ambiguous. How long will the stack view grow with the label (if the label value is dynamic)?
Hope this can fix your issue.
Just set number of lines to 0 in Attribute inspector for label. It will work for you.
Setting preferredMaxLayoutWidth to the UILabel worked for me
self.myLabel.preferredMaxLayoutWidth = self.bounds.size.width;
The following is a Playground implementation of multi-line label with a line break inside a UIStackView. It doesn't require embedding the UILabel inside anything and has been tested with Xcode 9.2 and Swift 4. Hope it's helpful.
import UIKit
import PlaygroundSupport
let containerView = UIView()
containerView.frame = CGRect.init(x: 0, y: 0, width: 400, height: 500)
containerView.backgroundColor = UIColor.white
var label = UILabel.init()
label.textColor = .black
label.numberOfLines = 0
label.translatesAutoresizingMaskIntoConstraints = false
label.text = "This is an example of sample text that goes on for a long time. This is an example of sample text that goes on for a long time."
let stackView = UIStackView.init(arrangedSubviews: [label])
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .vertical
stackView.distribution = .fill
stackView.alignment = .fill
containerView.addSubview(stackView)
stackView.centerXAnchor.constraint(equalTo: containerView.centerXAnchor).isActive = true
stackView.centerYAnchor.constraint(equalTo: containerView.centerYAnchor).isActive = true
stackView.widthAnchor.constraint(equalTo: containerView.widthAnchor).isActive = true
stackView.heightAnchor.constraint(equalTo: containerView.heightAnchor).isActive = true
PlaygroundPage.current.liveView = containerView
iOS 9+
Call [textLabel sizeToFit] after setting the UILabel's text.
sizeToFit will re-layout the multiline label using preferredMaxWidth. The label will resize the stackView, which will resize the cell. No additional constraints besides pinning the stack view to the content view are required.
Add UIStackView properties,
stackView.alignment = .fill
stackView.distribution = .fillProportionally
stackView.spacing = 8.0
stackView.axis = .horizontal
Instead of adding label inside UIView which is not required.If you are using inside UITableViewCell please, reload data on rotation.
The magic trick for me was to set a widthAnchor to the UIStackView.
Setting leadingAnchor and trailingAnchor won't work, but setting centerXAnchor and widthAnchor made the UILabel display correctly.
Here's a full example of a vertical UIStackView made up of multiline UILabels with automatic height.
The labels wrap based on the stackview's width and the stackview's height is based on the label's wrapped height. (With this approach you don't need to embed the labels in a UIView.) (Swift 5, iOS 12.2)
// A vertical stackview with multiline labels and automatic height.
class ThreeLabelStackView: UIStackView {
let label1 = UILabel()
let label2 = UILabel()
let label3 = UILabel()
init() {
super.init(frame: .zero)
self.translatesAutoresizingMaskIntoConstraints = false
self.axis = .vertical
self.distribution = .fill
self.alignment = .fill
label1.numberOfLines = 0
label2.numberOfLines = 0
label3.numberOfLines = 0
label1.lineBreakMode = .byWordWrapping
label2.lineBreakMode = .byWordWrapping
label3.lineBreakMode = .byWordWrapping
self.addArrangedSubview(label1)
self.addArrangedSubview(label2)
self.addArrangedSubview(label3)
// (Add some test data, a little spacing, and the background color
// make the labels easier to see visually.)
self.spacing = 1
label1.backgroundColor = .orange
label2.backgroundColor = .orange
label3.backgroundColor = .orange
label1.text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi."
label2.text = "Hello darkness my old friend..."
label3.text = "When I wrote the following pages, or rather the bulk of them, I lived alone, in the woods, a mile from any neighbor, in a house which I had built myself, on the shore of Walden Pond, in Concord, Massachusetts, and earned my living by the labor of my hands only."
}
required init(coder: NSCoder) { fatalError("init(coder:) has not been implemented") }
}
Here is a sample ViewController that uses it.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let myLabelStackView = ThreeLabelStackView()
self.view.addSubview(myLabelStackView)
// Set stackview width to its superview.
let widthConstraint = NSLayoutConstraint(item: myLabelStackView, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: self.view, attribute: NSLayoutConstraint.Attribute.width, multiplier: 1, constant: 0)
self.view.addConstraints([widthConstraint])
}
}
System layout should figure out origin, width and height to draw it subviews, in this case all of your subviews has same priority, that point make conflict, layout system don't known dependencies between views, which one draw first, second and so on
Set stack subviews compression will solve problem with multiple line, depending on your stack view is horizontal or vertical and which one you want to become multiple lines. stackOtherSubviews .setContentCompressionResistancePriority(.defaultHight, for: .horizontal)
lblTitle.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
After trying all above suggestion I found no properties change is need for the UIStackView. I just change the properties of the UILabels as following (The labels are added to a vertical stack view already):
Swift 4 example:
[titleLabel, subtitleLabel].forEach(){
$0.numberOfLines = 0
$0.lineBreakMode = .byWordWrapping
$0.setContentCompressionResistancePriority(UILayoutPriority.required, for: .vertical)
}
In my case, I followed the previous suggestions, but my text was still getting truncated to a single line though only in landscape. Turns out, I found an invisible \0 null character in the label's text which was the culprit. It must have been introduced alongside the em dash symbol I had inserted. To see if this is also happening in your case, use the View Debugger to select your label and inspect its text.
Xcode 9.2:
Just set number of lines to 0. Storyboard will look weird after setting this. Don't worry run the project. While running everything will resize according to your storyboard setup. I think its kind of bug in storyboard.
Tips : Set "number of liner to 0" in the last. reset it when you want to edit some other view and set to 0 after editing.
What worked for me!
stackview: alignment: fill, distribution: fill, constraint proportional width to superview ex. 0.8,
label: center, and lines = 0
For anyone who still cannot make it work. Try to set Autoshrink with a minimum Font Scale on that UILabel.
It's almost like @Andy's Answer,
but you can add your UILabel in extra UIStackview, vertical worked for me.
来源：https://stackoverflow.com/questions/34386528/multiline-label-in-uistackview