Changing specific text's color using NSMutable

Question

The issue I am having is that I want to be able to change the textColor of certain text in a TextView. I am using a concatenated string, and just want the strings I am appending into the TextView's text. It appears that what I want to use is NSMutableAttributedString, but I am not finding any resources of how to use this in Swift. What I have so far is something like this:

let string = "A \(stringOne) with \(stringTwo)"
var attributedString = NSMutableAttributedString(string: string)
textView.attributedText = attributedString

From here I know I need to find the range of words that need to have their textColor changed and then add them to the attributed string. What I need to know is how to find the correct strings from the attributedString, and then change their textColor.

Since I have too low of a rating I can't answer my own question, but here is the answer I found

I found my own answer by translating from translating some code from

Change attributes of substrings in a NSAttributedString

Here is the example of implementation in Swift:

let string = "A \(stringOne) and \(stringTwo)"
var attributedString = NSMutableAttributedString(string:string)

let stringOneRegex = NSRegularExpression(pattern: nameString, options: nil, error: nil)
let stringOneMatches = stringOneRegex.matchesInString(longString, options: nil, range: NSMakeRange(0, attributedString.length))
for stringOneMatch in stringOneMatches {
    let wordRange = stringOneMatch.rangeAtIndex(0)
    attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.nameColor(), range: wordRange)
}

textView.attributedText = attributedString

Since I am wanting to change the textColor of multiple Strings I will make a helper function to handle this, but this works for changing the textColor.

Answer 1

Based on the answers before I created a string extension

extension String {

func highlightWordsIn(highlightedWords: String, attributes: [[NSAttributedStringKey: Any]]) -> NSMutableAttributedString {
     let range = (self as NSString).range(of: highlightedWords)
     let result = NSMutableAttributedString(string: self)

     for attribute in attributes {
         result.addAttributes(attribute, range: range)
     }

     return result
    }
}

You can pass the attributes for the text to the method

Call like this

  let attributes = [[NSAttributedStringKey.foregroundColor:UIColor.red], [NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: 17)]]
  myLabel.attributedText = "This is a text".highlightWordsIn(highlightedWords: "is a text", attributes: attributes)

Answer 2

This might be work for you

let main_string = " User not found,Want to review ? Click here"
    let string_to_color = "Click here"

    let range = (main_string as NSString).range(of: string_to_color)

    let attribute = NSMutableAttributedString.init(string: main_string)
    attribute.addAttribute(NSAttributedStringKey.foregroundColor, value: UIColor.blue , range: range)

    lblClickHere.attributedText = attribute

Answer 3

Swift 4.1

NSAttributedStringKey.foregroundColor

for example if you want to change font in NavBar:

self.navigationController?.navigationBar.titleTextAttributes = [ NSAttributedStringKey.font: UIFont.systemFont(ofSize: 22), NSAttributedStringKey.foregroundColor: UIColor.white]

Answer 4

Swift 2.1 Update:

 let text = "We tried to make this app as most intuitive as possible for you. If you have any questions don't hesitate to ask us. For a detailed manual just click here."
 let linkTextWithColor = "click here"

 let range = (text as NSString).rangeOfString(linkTextWithColor)

 let attributedString = NSMutableAttributedString(string:text)
 attributedString.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor() , range: range)

 self.helpText.attributedText = attributedString

self.helpText is a UILabel outlet.

Answer 5

Answer is already given in previous posts but i have a different way of doing this

Swift 3x :

var myMutableString = NSMutableAttributedString()

myMutableString = NSMutableAttributedString(string: "Your full label textString")

myMutableString.setAttributes([NSFontAttributeName : UIFont(name: "HelveticaNeue-Light", size: CGFloat(17.0))!
        , NSForegroundColorAttributeName : UIColor(red: 232 / 255.0, green: 117 / 255.0, blue: 40 / 255.0, alpha: 1.0)], range: NSRange(location:12,length:8)) // What ever range you want to give

yourLabel.attributedText = myMutableString

Hope this helps anybody!

Answer 6

You can use this method. I implemented this method in my common utility class to access globally.

func attributedString(with highlightString: String, normalString: String, highlightColor: UIColor) -> NSMutableAttributedString {
    let attributes = [NSAttributedString.Key.foregroundColor: highlightColor]
    let attributedString = NSMutableAttributedString(string: highlightString, attributes: attributes)
    attributedString.append(NSAttributedString(string: normalString))
    return attributedString
}