Adjust UILabel height to text

Question

I've just put this in a playground and it works for me.

Updated for Swift 4.0

import UIKit

 func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat{
    let label:UILabel = UILabel(frame: CGRectMake(0, 0, width, CGFloat.greatestFiniteMagnitude))
    label.numberOfLines = 0
    label.lineBreakMode = NSLineBreakMode.byWordWrapping
    label.font = font
    label.text = text

    label.sizeToFit()
    return label.frame.height
}

let font = UIFont(name: "Helvetica", size: 20.0)

var height = heightForView("This is just a load of text", font: font, width: 100.0)

Swift 3:

func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat{
    let label:UILabel = UILabel(frame: CGRect(x: 0, y: 0, width: width, height: CGFloat.greatestFiniteMagnitude))
    label.numberOfLines = 0
    label.lineBreakMode = NSLineBreakMode.byWordWrapping
    label.font = font
    label.text = text
    label.sizeToFit()

    return label.frame.height
}

If you are using AutoLayout, you can adjust UILabel height by config UI only.

For iOS8 or above

• Set constraint leading/trailing for your UILabel
• And change the lines of UILabel from 1 to 0

For iOS7

• First, you need to add contains height for UILabel
• Then, modify the Relation from Equal to Greater than or Equal

• Finally, change the lines of UILabel from 1 to 0

Your UILabel will automatically increase height depending on the text

I have the strong working solution.

in layoutSubviews:

title.frame = CGRect(x: 0, y: 0, width: bounds.width, height: 0)
title.sizeToFit()
title.frame.size = title.bounds.size

in text setter:

title.text = newValue
setNeedsLayout()

UPD. of course with this UILabel settings:

title.lineBreakMode = .byWordWrapping
title.numberOfLines = 0

I create this extension if you want

extension UILabel {
    func setSizeFont (sizeFont: CGFloat) {
        self.font =  UIFont(name: self.font.fontName, size: sizeFont)!
        self.sizeToFit()
    }
}

based on Anorak's answer, I also agree with Zorayr's concern, so I added a couple of lines to remove the UILabel and return only the CGFloat, I don't know if it helps since the original code doesn't add the UIabel, but it doesn't throw error, so I'm using the code below:

func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat{

    var currHeight:CGFloat!

    let label:UILabel = UILabel(frame: CGRectMake(0, 0, width, CGFloat.max))
    label.numberOfLines = 0
    label.lineBreakMode = NSLineBreakMode.ByWordWrapping
    label.font = font
    label.text = text
    label.sizeToFit()

    currHeight = label.frame.height
    label.removeFromSuperview()

    return currHeight
}

In swift 4.1 and Xcode 9.4.1

Only 3 steps

Step 1)

//To calculate height for label based on text size and width
func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat {
    let label:UILabel = UILabel(frame: CGRect(x: 0, y: 0, width: width, height: CGFloat.greatestFiniteMagnitude))
    label.numberOfLines = 0
    label.lineBreakMode = NSLineBreakMode.byWordWrapping
    label.font = font
    label.text = text

    label.sizeToFit()
    return label.frame.height
}

Step 2)

//Call this function
let height = heightForView(text: "This is your text", font: UIFont.systemFont(ofSize: 17), width: 300)
print(height)//Output : 41.0

Step 3)

//This is your label
let proNameLbl = UILabel(frame: CGRect(x: 0, y: 20, width: 300, height: height))
proNameLbl.text = "This is your text"
proNameLbl.font = UIFont.systemFont(ofSize: 17)
proNameLbl.numberOfLines = 0
proNameLbl.lineBreakMode = .byWordWrapping
infoView.addSubview(proNameLbl)

Just by setting:

label.numberOfLines = 0

The label automatically adjusts its height based upon the amount of text entered.