ios - 用 attributedText 给 UILabel 上色

Question

你好我正在做一个 Twitter 应用程序，我想给主题标签、用户名和 URL 上色这是我的手机上的课

class TweetTableViewCell: UITableViewCell
{
var tweet: Tweet? {
    didSet {
        updateUI()
    }
}

@IBOutlet weak var tweetProfileImageView: UIImageView!
@IBOutlet weak var tweetScreenNameLabel: UILabel!
@IBOutlet weak var tweetTextLabel: UILabel!
@IBOutlet weak var tweetCreatedLabel: UILabel!

func updateUI() {

    tweetTextLabel?.attributedText = nil
    tweetScreenNameLabel?.text = nil
    tweetProfileImageView?.image = nil
    tweetCreatedLabel?.text = nil


    if let tweet = self.tweet
    {
        tweetTextLabel?.text = tweet.text
        if tweetTextLabel?.text != nil  {
            for _ in tweet.media {
                tweetTextLabel.text! += " 📷"
            }
            for user in tweet.userMentions{

                    tweetTextLabel.attributedText = NSAttributedString(string:"\(user.keyword)")




            }
        }

        tweetScreenNameLabel?.text = "\(tweet.user)"

        if let profileImageURL = tweet.user.profileImageURL {
            let qos = Int(QOS_CLASS_USER_INITIATED.value)
            dispatch_async(dispatch_get_global_queue(qos, 0)) { () -> Void in
                if let imageData = NSData(contentsOfURL: profileImageURL) {
                     dispatch_async(dispatch_get_main_queue()){
                    if profileImageURL == tweet.user.profileImageURL{
                         self.tweetProfileImageView?.image = UIImage(data: imageData)
                        }
                    }}
                }
        }


        let formatter = NSDateFormatter()
        if NSDate().timeIntervalSinceDate(tweet.created) > 24*60*60 {
            formatter.dateStyle = NSDateFormatterStyle.ShortStyle
        } else {
            formatter.timeStyle = NSDateFormatterStyle.ShortStyle
        }
        tweetCreatedLabel?.text = formatter.stringFromDate(tweet.created)
    }

}

问题就在这里

 for user in tweet.userMentions{
                    tweetTextLabel.attributedText = NSMutableAttributedString(string:"\(user.keyword)")

            }

我不知道如何给它上色(attributedText)。我有带主题标签的字符串，用户名。我正在尝试使用用户名

更新

for user in tweet.userMentions{
                //tweetTextLabel.attributedText = NSMutableAttributedString(string:"\(user.keyword)")
                var attributedText =  tweetTextLabel.attributedText
                var userName:NSString = user.keyword
                var atrString = NSMutableAttributedString(string:tweetTextLabel.text!)
               atrString.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor(), range: fullString.rangeOfString(userName))
                attributedText = atrString


            }

并且是这样说的；它之前是有效的:使用未解析的标识符“fullString”

Answer 1

试试这个:

var attrs = [NSForegroundColorAttributeName : UIColor.redColor()]
var atrText = NSMutableAttributedString(string:"text", attributes:attrs)
tweetTextLabel.attributedText = atrText;