How to Change Color of Text Strings Inside Uitextview in Swift3

How to change color of text strings inside UITextView in Swift3

In this I have taken string "world" as example. When you r typing in textview then This method is in working

func textViewDidChange(_ textView: UITextView) {
        let attrStr = NSMutableAttributedString(string:txtview.text)
        let inputLength = attrStr.string.characters.count
        let searchString = "world"
        let searchLength = searchString.characters.count
        var range = NSRange(location: 0, length: attrStr.length)

        while (range.location != NSNotFound) {
            range = (attrStr.string as NSString).range(of: searchString, options: [], range: range)
            if (range.location != NSNotFound) {
                attrStr.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: range.location, length: searchLength))
                range = NSRange(location: range.location + range.length, length: inputLength - (range.location + range.length))
                textView.attributedText = attrStr
            }
        }    
}

But when You have already set initial text of textview then use this method

func textViewDidBeginEditing(_ textView: UITextView) {
        //Just set your text as you set in textview
        let attrStr = NSMutableAttributedString(string: "hello world I ma jeckjklwefljlwjflkjwfkljelwfjklfgjwklfjlkwgjwlgkjwklsgjklsjgklsdjgkljdslkgjsdlkgjlksdjgldjsgldjskl world nsfhjklshfklhsllsd fgiw world")
        let inputLength = attrStr.string.characters.count
        let searchString = "world"
        let searchLength = searchString.characters.count
        var range = NSRange(location: 0, length: attrStr.length)

        while (range.location != NSNotFound) {
            range = (attrStr.string as NSString).range(of: searchString, options: [], range: range)
            if (range.location != NSNotFound) {
                attrStr.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: range.location, length: searchLength))
                range = NSRange(location: range.location + range.length, length: inputLength - (range.location + range.length))
                textView.attributedText = attrStr
            }
          }  
  }

For Multiple Strings, You can do like this SWIFT 3

func textViewDidChange(_ textView: UITextView) {
        let attrStr = NSMutableAttributedString(string: txtview.text)
        let inputLength = attrStr.string.characters.count
        let searchString : NSArray = NSArray.init(objects: "hello","world")
        for i in 0...searchString.count-1
        {

             let string : String = searchString.object(at: i) as! String
             let searchLength = string.characters.count
             var range = NSRange(location: 0, length: attrStr.length)

             while (range.location != NSNotFound) {
                 range = (attrStr.string as NSString).range(of: string, options: [], range: range)
                 if (range.location != NSNotFound) {
                 attrStr.addAttribute(NSForegroundColorAttributeName, value: UIColor.red, range: NSRange(location: range.location, length: searchLength))
                 range = NSRange(location: range.location + range.length, length: inputLength - (range.location + range.length))
                 textView.attributedText = attrStr
        }
    }   
  }
}

OBJECTIVE C
For Multiple Strings, You can do like this

-(void)textViewDidChange:(UITextView *)textView
{
    NSMutableAttributedString *attstr = [[NSMutableAttributedString alloc]initWithString:textView.text];
    NSUInteger characterCount = [attstr length];
    NSArray *arr = [[NSArray alloc]initWithObjects:@"football",@"player",nil];

    for (int i=0; i<arr.count; i++) {

    NSUInteger searchlength = [[NSString stringWithFormat:@"%@",[arr objectAtIndex:i]] length];
    NSRange range1 = NSMakeRange(0, attstr.length);

    while (range1.location != NSNotFound) {
        range1 =[attstr.string rangeOfString:[NSString stringWithFormat:@"%@",[arr objectAtIndex:i]] options:0 range:range1];
        if (range1.location !=NSNotFound) {
            [attstr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(range1.location, searchlength)];
            [attstr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:20.0]  range:range1];
            range1 = NSMakeRange(range1.location + range1.length, characterCount -(range1.location + range1.length));
            textView.attributedText = attstr;
        }
    }
}

UITextView change text color of specific text

Sorry, I just noticed your message. Here is a working example (tested in a playground):

import UIKit

func apply (string: NSMutableAttributedString, word: String) -> NSMutableAttributedString {
    let range = (string.string as NSString).rangeOfString(word)
    return apply(string, word: word, range: range, last: range)
}

func apply (string: NSMutableAttributedString, word: String, range: NSRange, last: NSRange) -> NSMutableAttributedString {
    if range.location != NSNotFound {
        string.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor(), range: range)
        let start = last.location + last.length
        let end = string.string.characters.count - start
        let stringRange = NSRange(location: start, length: end)
        let newRange = (string.string as NSString).rangeOfString(word, options: [], range: stringRange)
        apply(string, word: word, range: newRange, last: range)
    }
    return string
}

var chordsArray = ["Cmaj", "Bbmaj7"]
var text = "Cmaj Bbmaj7 I Love Swift Cmaj Bbmaj7 Swift"
var newText = NSMutableAttributedString(string: text)

for word in chordsArray {
    newText = apply(newText, word: word)
}

newText

Is it possible to change color of single word in UITextView and UITextField

Yes you need to use NSAttributedString for that, find the RunningAppHere.

Scan through the word and find the range of your word and change its color.

EDIT:

- (IBAction)colorWord:(id)sender {
    NSMutableAttributedString * string = [[NSMutableAttributedString alloc]initWithString:self.text.text];

    NSArray *words=[self.text.text componentsSeparatedByString:@" "];

    for (NSString *word in words) {        
        if ([word hasPrefix:@"@"]) {
            NSRange range=[self.text.text rangeOfString:word];
            [string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:range];           
        }
    }
    [self.text setAttributedText:string];
}

EDIT 2 : see the screenshot

UITextView Color of the selected text

If you just want to change the selected range of the string, you must change the attributedText property. You can do something like:

@IBAction func didTapButton(sender: UIButton) {
    let range = textView.selectedRange
    let string = NSMutableAttributedString(attributedString: textView.attributedText)
    let attributes = [NSForegroundColorAttributeName: UIColor.redColor()]
    string.addAttributes(attributes, range: textView.selectedRange)
    textView.attributedText = string
    textView.selectedRange = range
}

If you want to change the whole string, you can use the technique suggested by CeceXX.

@IBAction func didTapButton(sender: UIButton) {
    textView.textColor = UIColor.redColor()
}

How can I change style of some words in my UITextView one by one in Swift?

Use a timer. Stash matches in a property. Stash the base unhighlighted attributed string in a property. Now have your timer highlight the first match and call itself again in 1 second, highlighting up to the second match and repeat until there are no matches left.

    func highlight (to index: Int = 0) {
        guard index < matches.count else {
            return
        }
        let titleDict: NSDictionary = [NSForegroundColorAttributeName: orangeColor]
        let attributedString = NSMutableAttributedString(attributedString: storedAttributedString)
        for i in 0..< index {
            let matchRange = matches[i].rangeAt(0)
            attributedString.addAttributes(titleDict as! [String : AnyObject], range: matchRange)
        }
        self.attributedText = attributedString
        let _ = Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { _ in
            self.highlight(to: index + 1)
        }
    }

Swiftui using UITextVIew for hyperlink but can't change text color

Here is what I meant. Tested with Xcode 13.3 / iOS 15.4

*Red color used for better visibility

func updateUIView(_ uiView: UITextView, context: Context) {
    let attributedOriginalText = NSMutableAttributedString(string: text)

    for (urlString, hyperLink) in links {
        let linkRange = attributedOriginalText.mutableString.range(of: hyperLink)
        attributedOriginalText.addAttribute(.link, value: urlString, range: linkRange)
    }

    let fullRange = NSRange(location: 0, length: attributedOriginalText.length)
    attributedOriginalText.addAttribute(.foregroundColor, value: UIColor.red, range: fullRange)

    uiView.attributedText = attributedOriginalText
    uiView.linkTextAttributes = [
        .underlineStyle : NSUnderlineStyle.single.rawValue,
        .foregroundColor: UIColor.red
    ]

Can I change the color of auto detected links on UITextView?

On iOS 7 you can set the tintColor of the UITextView. It affects the link color as well as the cursor line and the selected text color.

iOS 7 also added a new property to UITextView called linkTextAttributes which would appear to let you fully control the link style.

iOS Swift Change Particular Text Color Inside Label Programatically

You can use following code to search in string

    //Text need to be searched
    let SearchAttributeText = "the"

    //Store label text in variable as NSString
    let contentString = lblContent.text! as NSString

    //Create range of label text
    var rangeString = NSMakeRange(0, contentString.length)

    //Convert label text into attributed string
    let attribute = NSMutableAttributedString.init(string: contentString as String)

    while (rangeString.length != NSNotFound && rangeString.location != NSNotFound) {

        //Get the range of search text
        let colorRange = (lblContent.text?.lowercased() as! NSString).range(of: SearchAttributeText, options: NSString.CompareOptions(rawValue: 0), range: rangeString)

        if (colorRange.location == NSNotFound) {
            //If location is not present in the string the loop will break
            break
        } else {
            //This line of code colour the searched text
            attribute.addAttribute(NSAttributedStringKey.foregroundColor, value: UIColor.red , range: colorRange)
            lblContent.attributedText = attribute

            //This line of code increment the rangeString variable
            rangeString = NSMakeRange(colorRange.location + colorRange.length, contentString.length - (colorRange.location + colorRange.length))
        }
    }

The below line of code update the range by incrementing the location and length parameter of NSRange

rangeString = NSMakeRange(colorRange.location + colorRange.length, contentString.length - (colorRange.location + colorRange.length))

How get textview attributed text?

You need to get the attributedText from the UITextView and then append new text to it like:

let existingText = myTextView.attributedText
let mutableText = NSAttributedString(attributedString: existingText)

// Then add your text

Check NSMutableAttributedString docs for how to do the last part.

---

Related Topics