我写了helper来方便地添加属性:

- (void)addColor:(UIColor *)color substring:(NSString *)substring;
- (void)addBackgroundColor:(UIColor *)color substring:(NSString *)substring;
- (void)addUnderlineForSubstring:(NSString *)substring;
- (void)addStrikeThrough:(int)thickness substring:(NSString *)substring;
- (void)addShadowColor:(UIColor *)color width:(int)width height:(int)height radius:(int)radius substring:(NSString *)substring;
- (void)addFontWithName:(NSString *)fontName size:(int)fontSize substring:(NSString *)substring;
- (void)addAlignment:(NSTextAlignment)alignment substring:(NSString *)substring;
- (void)addColorToRussianText:(UIColor *)color;
- (void)addStrokeColor:(UIColor *)color thickness:(int)thickness substring:(NSString *)substring;
- (void)addVerticalGlyph:(BOOL)glyph substring:(NSString *)substring;

https://github.com/shmidt/MASAttributes

你也可以通过CocoaPods安装:pod 'MASAttributes'， '~> 1.0.0'

带属性字符串扩展的更简单的解决方案。

extension NSMutableAttributedString {

    // this function attaches color to string    
    func setColorForText(textToFind: String, withColor color: UIColor) {
        let range: NSRange = self.mutableString.range(of: textToFind, options: .caseInsensitive)
        self.addAttribute(NSAttributedStringKey.foregroundColor, value: color, range: range)
    }

}

试试这个，看看(在Swift 3和4中测试)

let label = UILabel()
label.frame = CGRect(x: 120, y: 100, width: 200, height: 30)
let first = "first"
let second = "second"
let third = "third"
let stringValue = "\(first)\(second)\(third)"  // or direct assign single string value like "firstsecondthird"

let attributedString: NSMutableAttributedString = NSMutableAttributedString(string: stringValue)
attributedString.setColorForText(textToFind: first, withColor: UIColor.red)   // use variable for string "first"
attributedString.setColorForText(textToFind: "second", withColor: UIColor.green) // or direct string like this "second"
attributedString.setColorForText(textToFind: third, withColor: UIColor.blue)
label.font = UIFont.systemFont(ofSize: 26)
label.attributedText = attributedString
self.view.addSubview(label)

以下是预期结果:

这个方法非常简单。

let text = "This is a colorful attributed string"
let attributedText = 
NSMutableAttributedString.getAttributedString(fromString: text)
attributedText.apply(color: .red, subString: "This")
//Apply yellow color on range
attributedText.apply(color: .yellow, onRange: NSMakeRange(5, 4))

更多详情请点击这里; https://github.com/iOSTechHub/AttributedString

在Swift 4中:

let string:NSMutableAttributedString = {

    let mutableString = NSMutableAttributedString(string: "firstsecondthird")

    mutableString.addAttribute(NSForegroundColorAttributeName, value: UIColor.red , range: NSRange(location: 0, length: 5))
    mutableString.addAttribute(NSForegroundColorAttributeName, value: UIColor.green , range: NSRange(location: 5, length: 6))
    mutableString.addAttribute(NSForegroundColorAttributeName, value: UIColor.blue , range: NSRange(location: 11, length: 5))
    return mutableString
}()

print(string)

这个解对任何长度都适用

NSString *strFirst = @"Anylengthtext";
NSString *strSecond = @"Anylengthtext";
NSString *strThird = @"Anylengthtext";

NSString *strComplete = [NSString stringWithFormat:@"%@ %@ %@",strFirst,strSecond,strThird];

NSMutableAttributedString *attributedString =[[NSMutableAttributedString alloc] initWithString:strComplete];

[attributedString addAttribute:NSForegroundColorAttributeName
              value:[UIColor redColor]
              range:[strComplete rangeOfString:strFirst]];

[attributedString addAttribute:NSForegroundColorAttributeName
              value:[UIColor yellowColor]
              range:[strComplete rangeOfString:strSecond]];

[attributedString addAttribute:NSForegroundColorAttributeName
              value:[UIColor blueColor]
              range:[strComplete rangeOfString:strThird]];


self.lblName.attributedText = attributedString;

你可以加载一个HTML带属性的字符串在Swift如下

   var Str = NSAttributedString(
   data: htmlstring.dataUsingEncoding(NSUnicodeStringEncoding, allowLossyConversion: true),
   options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
   documentAttributes: nil,
   error: nil)

   label.attributedText = Str  

从文件中加载html

   if let rtf = NSBundle.mainBundle().URLForResource("rtfdoc", withExtension: "rtf", subdirectory: nil, localization: nil) {

   let attributedString = NSAttributedString(fileURL: rtf, options: [NSDocumentTypeDocumentAttribute:NSRTFTextDocumentType], documentAttributes: nil, error: nil)
        textView.attributedText = attributedString
        textView.editable = false
    }

http://sketchytech.blogspot.in/2013/11/creating-nsattributedstring-from-html.html

和设置字符串根据您所需的属性....遵循这个. . http://makeapppie.com/2014/10/20/swift-swift-using-attributed-strings-in-swift/