在UILabel的末尾添加“... Read More”

Question

我有一个UILabel，在某些情况下，文本比UILabel本身更长，所以我看到文本为"bla bla bla..."我想在...Read More末尾添加一个UILabel按钮文本..

我已经阅读了一些帖子，但是他们提供的解决方案对我来说并不好，例如：计算将输入UILabel的字符数，但是我使用的字体每个字符都有不同的宽度。

我怎么能设法做到这一点？

提前致谢！

Answer 1

Swift4（IOS 11.2）

在没有操作的情况下在标签末尾阅读更多内容

extension UILabel {

    func addTrailing(with trailingText: String, moreText: String, moreTextFont: UIFont, moreTextColor: UIColor) {
        let readMoreText: String = trailingText + moreText

        let lengthForVisibleString: Int = self.visibleTextLength
        let mutableString: String = self.text!
        let trimmedString: String? = (mutableString as NSString).replacingCharacters(in: NSRange(location: lengthForVisibleString, length: ((self.text?.count)! - lengthForVisibleString)), with: "")
        let readMoreLength: Int = (readMoreText.count)
        let trimmedForReadMore: String = (trimmedString! as NSString).replacingCharacters(in: NSRange(location: ((trimmedString?.count ?? 0) - readMoreLength), length: readMoreLength), with: "") + trailingText
        let answerAttributed = NSMutableAttributedString(string: trimmedForReadMore, attributes: [NSAttributedStringKey.font: self.font])
        let readMoreAttributed = NSMutableAttributedString(string: moreText, attributes: [NSAttributedStringKey.font: moreTextFont, NSAttributedStringKey.foregroundColor: moreTextColor])
        answerAttributed.append(readMoreAttributed)
        self.attributedText = answerAttributed
    }

    var visibleTextLength: Int {
        let font: UIFont = self.font
        let mode: NSLineBreakMode = self.lineBreakMode
        let labelWidth: CGFloat = self.frame.size.width
        let labelHeight: CGFloat = self.frame.size.height
        let sizeConstraint = CGSize(width: labelWidth, height: CGFloat.greatestFiniteMagnitude)

        let attributes: [AnyHashable: Any] = [NSAttributedStringKey.font: font]
        let attributedText = NSAttributedString(string: self.text!, attributes: attributes as? [NSAttributedStringKey : Any])
        let boundingRect: CGRect = attributedText.boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, context: nil)

        if boundingRect.size.height > labelHeight {
            var index: Int = 0
            var prev: Int = 0
            let characterSet = CharacterSet.whitespacesAndNewlines
            repeat {
                prev = index
                if mode == NSLineBreakMode.byCharWrapping {
                    index += 1
                } else {
                    index = (self.text! as NSString).rangeOfCharacter(from: characterSet, options: [], range: NSRange(location: index + 1, length: self.text!.count - index - 1)).location
                }
            } while index != NSNotFound && index < self.text!.count && (self.text! as NSString).substring(to: index).boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, attributes: attributes as? [NSAttributedStringKey : Any], context: nil).size.height <= labelHeight
            return prev
        }
        return self.text!.count
    }
}

Swift 4.2

extension UILabel {

        func addTrailing(with trailingText: String, moreText: String, moreTextFont: UIFont, moreTextColor: UIColor) {
            let readMoreText: String = trailingText + moreText

            let lengthForVisibleString: Int = self.vissibleTextLength
            let mutableString: String = self.text!
            let trimmedString: String? = (mutableString as NSString).replacingCharacters(in: NSRange(location: lengthForVisibleString, length: ((self.text?.count)! - lengthForVisibleString)), with: "")
            let readMoreLength: Int = (readMoreText.count)
            let trimmedForReadMore: String = (trimmedString! as NSString).replacingCharacters(in: NSRange(location: ((trimmedString?.count ?? 0) - readMoreLength), length: readMoreLength), with: "") + trailingText
            let answerAttributed = NSMutableAttributedString(string: trimmedForReadMore, attributes: [NSAttributedString.Key.font: self.font])
            let readMoreAttributed = NSMutableAttributedString(string: moreText, attributes: [NSAttributedString.Key.font: moreTextFont, NSAttributedString.Key.foregroundColor: moreTextColor])
            answerAttributed.append(readMoreAttributed)
            self.attributedText = answerAttributed
        }

        var vissibleTextLength: Int {
            let font: UIFont = self.font
            let mode: NSLineBreakMode = self.lineBreakMode
            let labelWidth: CGFloat = self.frame.size.width
            let labelHeight: CGFloat = self.frame.size.height
            let sizeConstraint = CGSize(width: labelWidth, height: CGFloat.greatestFiniteMagnitude)

            let attributes: [AnyHashable: Any] = [NSAttributedString.Key.font: font]
            let attributedText = NSAttributedString(string: self.text!, attributes: attributes as? [NSAttributedString.Key : Any])
            let boundingRect: CGRect = attributedText.boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, context: nil)

            if boundingRect.size.height > labelHeight {
                var index: Int = 0
                var prev: Int = 0
                let characterSet = CharacterSet.whitespacesAndNewlines
                repeat {
                    prev = index
                    if mode == NSLineBreakMode.byCharWrapping {
                        index += 1
                    } else {
                        index = (self.text! as NSString).rangeOfCharacter(from: characterSet, options: [], range: NSRange(location: index + 1, length: self.text!.count - index - 1)).location
                    }
                } while index != NSNotFound && index < self.text!.count && (self.text! as NSString).substring(to: index).boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, attributes: attributes as? [NSAttributedString.Key : Any], context: nil).size.height <= labelHeight
                return prev
            }
            return self.text!.count
        }
    }

用法

let readmoreFont = UIFont(name: "Helvetica-Oblique", size: 11.0)
let readmoreFontColor = UIColor.blue
DispatchQueue.main.async {
    self.yourLabel.addTrailing(with: "... ", moreText: "Readmore", moreTextFont: readmoreFont!, moreTextColor: readmoreFontColor)
}

结果

注意： - Readmore不包括动作

Answer 2

行动

extension UILabel {
    var numberOfVisibleLines: Int {
        let textSize = CGSize(width: CGFloat(self.frame.size.width), height: CGFloat(MAXFLOAT))
        let rHeight: Int = lroundf(Float(self.sizeThatFits(textSize).height))
        let charSize: Int = lroundf(Float(self.font.pointSize))
        return rHeight / charSize
    }
}

Answer 3

Swift 4和Swift 5.我需要实现相同的功能。已经给出了答案，但根据我的说法，TTTAttributedLabel是最好的方法。它可以让您更好地控制内容。易于查找地址，链接，日期等。您还可以更改链接的颜色。 TTTAttributedLabel Library链接已在上面的答案中给出。让我们来实施。

 let tap = UITapGestureRecognizer(target: self, action: #selector(self.tapFunction))
 Urlabel.isUserInteractionEnabled = true
 Urlabel.addGestureRecognizer(tap)

 @objc
    func tapFunction(sender:UITapGestureRecognizer) {


    }

在这里，我创建了TTTAttributedLabel的扩展，并将ReadMore和ReadLess逻辑放在这里。你可以根据你的修改。

let kCharacterBeforReadMore =  20
let kReadMoreText           =  "...ReadMore"
let kReadLessText           =  "...ReadLess"

@IBOutlet weak var labelText: TTTAttributedLabel! // setYouLabel Class to TTTAttributedLabel in StoryBoard
var strFull = ""

 override func viewDidLoad() {
      super.viewDidLoad()
      strFull = "I need to implement the same. As answers are already given but according to me TTTAttributedLabel is the best way to do it. I gives I need to implement the same. As answers are already given but according to me TTTAttributedLabel is the best way to do it. I gives you"
      labelText.showTextOnTTTAttributeLable(str: strFull, readMoreText: kReadMoreText, readLessText: kReadLessText, font: UIFont.init(name: "Helvetica-Bold", size: 24.0)!, charatersBeforeReadMore: kCharacterBeforReadMore, activeLinkColor: UIColor.blue, isReadMoreTapped: false, isReadLessTapped: false)
      labelText.delegate = self
   }
      func readMore(readMore: Bool) {
        labelText.showTextOnTTTAttributeLable(str: strFull, readMoreText: kReadMoreText, readLessText: kReadLessText, font: nil, charatersBeforeReadMore: kCharacterBeforReadMore, activeLinkColor: UIColor.blue, isReadMoreTapped: readMore, isReadLessTapped: false)
      }
      func readLess(readLess: Bool) {
        labelText.showTextOnTTTAttributeLable(str: strFull, readMoreText: kReadMoreText, readLessText: kReadLessText, font: nil, charatersBeforeReadMore: kCharacterBeforReadMore, activeLinkColor: UIColor.blue, isReadMoreTapped: readLess, isReadLessTapped: true)
      }
}

您需要实现TTTAttributedLabel的didSelectLinkWithTransitInformation委托。在这里，您可以获得已通过的组件

 extension TTTAttributedLabel {
      func showTextOnTTTAttributeLable(str: String, readMoreText: String, readLessText: String, font: UIFont?, charatersBeforeReadMore: Int, activeLinkColor: UIColor, isReadMoreTapped: Bool, isReadLessTapped: Bool) {

        let text = str + readLessText
        let attributedFullText = NSMutableAttributedString.init(string: text)
        let rangeLess = NSString(string: text).range(of: readLessText, options: String.CompareOptions.caseInsensitive)
//Swift 5
       // attributedFullText.addAttributes([NSAttributedStringKey.foregroundColor : UIColor.blue], range: rangeLess)
        attributedFullText.addAttributes([NSAttributedString.Key.foregroundColor : UIColor.blue], range: rangeLess)

        var subStringWithReadMore = ""
        if text.count > charatersBeforeReadMore {
          let start = String.Index(encodedOffset: 0)
          let end = String.Index(encodedOffset: charatersBeforeReadMore)
          subStringWithReadMore = String(text[start..<end]) + readMoreText
        }

        let attributedLessText = NSMutableAttributedString.init(string: subStringWithReadMore)
        let nsRange = NSString(string: subStringWithReadMore).range(of: readMoreText, options: String.CompareOptions.caseInsensitive)
        //Swift 5
       // attributedLessText.addAttributes([NSAttributedStringKey.foregroundColor : UIColor.blue], range: nsRange)
        attributedLessText.addAttributes([NSAttributedString.Key.foregroundColor : UIColor.blue], range: nsRange)
        if let _ = font {
         self.font = font
        }
        self.attributedText = attributedLessText
        self.activeLinkAttributes = [NSAttributedString.Key.foregroundColor : UIColor.blue]
        //Swift 5
       // self.linkAttributes = [NSAttributedStringKey.foregroundColor : UIColor.blue]
        self.linkAttributes = [NSAttributedString.Key.foregroundColor : UIColor.blue]
        self.addLink(toTransitInformation: ["ReadMore":"1"], with: nsRange)

        if isReadMoreTapped {
          self.numberOfLines = 0
          self.attributedText = attributedFullText
          self.addLink(toTransitInformation: ["ReadLess": "1"], with: rangeLess)
        }
        if isReadLessTapped {
          self.numberOfLines = 3
          self.attributedText = attributedLessText
        }
      }
    }

结果 - 在点击ReadMore之前

extension ViewController: TTTAttributedLabelDelegate { func attributedLabel(_ label: TTTAttributedLabel!, didSelectLinkWithTransitInformation components: [AnyHashable : Any]!) { if let _ = components as? [String: String] { if let value = components["ReadMore"] as? String, value == "1" { self.readMore(readMore: true) } if let value = components["ReadLess"] as? String, value == "1" { self.readLess(readLess: true) } } } }

结果 - 点击ReadMore后

Answer 4

你知道UILabel没有触摸动作吗？所以你不能触摸'...阅读更多'如果UILabel中的全文。

注意：我的解决方案是，添加UILabel的清晰背景按钮结束。

Answer 5

所以我这样做是为了向Qazxswpoi，UITextView或UITextField添加Read More ...按钮：

UILabel

使用- (void)addReadMoreStringToUILabel:(UILabel*)label { NSString *readMoreText = @" ...Read More"; NSInteger lengthForString = label.text.length; if (lengthForString >= 30) { NSInteger lengthForVisibleString = [self fitString:label.text intoLabel:label]; NSMutableString *mutableString = [[NSMutableString alloc] initWithString:label.text]; NSString *trimmedString = [mutableString stringByReplacingCharactersInRange:NSMakeRange(lengthForVisibleString, (label.text.length - lengthForVisibleString)) withString:@""]; NSInteger readMoreLength = readMoreText.length; NSString *trimmedForReadMore = [trimmedString stringByReplacingCharactersInRange:NSMakeRange((trimmedString.length - readMoreLength), readMoreLength) withString:@""]; NSMutableAttributedString *answerAttributed = [[NSMutableAttributedString alloc] initWithString:trimmedForReadMore attributes:@{ NSFontAttributeName : label.font }]; NSMutableAttributedString *readMoreAttributed = [[NSMutableAttributedString alloc] initWithString:readMoreText attributes:@{ NSFontAttributeName : Font(TWRegular, 12.), NSForegroundColorAttributeName : White }]; [answerAttributed appendAttributedString:readMoreAttributed]; label.attributedText = answerAttributed; UITagTapGestureRecognizer *readMoreGesture = [[UITagTapGestureRecognizer alloc] initWithTarget:self action:@selector(readMoreDidClickedGesture:)]; readMoreGesture.tag = 1; readMoreGesture.numberOfTapsRequired = 1; [label addGestureRecognizer:readMoreGesture]; label.userInteractionEnabled = YES; } else { NSLog(@"No need for 'Read More'..."); } }方法可以找到fitString:intoLabel。

至于here只是一个正常的UITagTapGestureRecognizer子类，带有一个名为tag的UITapGestureRecognizer属性。我之所以这样做，是因为我想确定点击哪个NSInteger，我在同一个Read More...中有不止一个。你可以使用正常的UIViewController。

请享用！

Answer 6

Tttattributed标签具有此功能

UITapGestureRecognizer

您需要将“截断”标记设置为“阅读更多...”

看到

attributedTruncationToken

https://github.com/TTTAttributedLabel/TTTAttributedLabel

Answer 7

这适用于Swift 4.2

这是@ ramchandran答案的更安全版本，因为您不知道用户将输入多少个字符。

在他的回答中，如果用户输入的字符串的长度小于您决定用于var subTitleLabel = TTTAttributedLabel(frame : frame) self.addSubview(subTitleLabel) var trunc = NSMutableAttributedString(string: "...more") trunc.addAttribute(NSFontAttributeName, value: UIFont.systemFontOfSize(12), range: NSMakeRange(0, 7)) trunc.addAttribute(NSForegroundColorAttributeName, value: UIColor.blueColor(), range: NSMakeRange(0, 7)) subTitleLabel.attributedTruncationToken = trunc subTitleLabel.numberOfLines = 1 subTitleLabel.autoresizingMask = UIViewAutoresizing.FlexibleHeight | UIViewAutoresizing.FlexibleWidth的任何文本的长度，那么它将崩溃。例如，这就是你如何使用它

... Readmore

在上面的例子中，if yourLabel.text!.count > 1 { let readmoreFont = UIFont(name: "Helvetica-Oblique", size: 11.0) let readmoreFontColor = UIColor.blue DispatchQueue.main.async { self.yourLabel.addTrailing(with: "... ", moreText: "Readmore", moreTextFont: readmoreFont!, moreTextColor: readmoreFontColor) } }的输出总共为12个字符。如果用户输入的字符串是... Readmore，那么字符串的文本将只有8个字符。它会崩溃，因为下面一行中使用yourLabel.text = "12345678"的范围会产生负面结果：

((trimmedString?.count ?? 0) - readMoreLength)

我添加了一个安全检查，以确保如果输入的字符串小于或等于你决定用作// “12345678” minus “... Readmore” = negative four (8 - 12 = -4) let trimmedForReadMore: String = (trimmedString! as NSString).replacingCharacters(in: NSRange(location: ((trimmedString?.count ?? 0) - readMoreLength), length: readMoreLength), with: "") + trailingText的字符数，它将返回并且将导致崩溃的行永远不会到达：

... Readmore

它位于// trimmedString is the string the user entered guard let safeTrimmedString = trimmedString else { return } if safeTrimmedString.count <= readMoreLength { return }功能的中心

addTrailing

Answer 8

您可以尝试第三个图书馆extension UILabel{ func addTrailing(with trailingText: String, moreText: String, moreTextFont: UIFont, moreTextColor: UIColor) { let readMoreText: String = trailingText + moreText if self.visibleTextLength == 0 { return } let lengthForVisibleString: Int = self.visibleTextLength if let myText = self.text { let mutableString: String = myText let trimmedString: String? = (mutableString as NSString).replacingCharacters(in: NSRange(location: lengthForVisibleString, length: myText.count - lengthForVisibleString), with: "") let readMoreLength: Int = (readMoreText.count) guard let safeTrimmedString = trimmedString else { return } if safeTrimmedString.count <= readMoreLength { return } print("this number \(safeTrimmedString.count) should never be less\n") print("then this number \(readMoreLength)") // "safeTrimmedString.count - readMoreLength" should never be less then the readMoreLength because it'll be a negative value and will crash let trimmedForReadMore: String = (safeTrimmedString as NSString).replacingCharacters(in: NSRange(location: safeTrimmedString.count - readMoreLength, length: readMoreLength), with: "") + trailingText let answerAttributed = NSMutableAttributedString(string: trimmedForReadMore, attributes: [NSAttributedString.Key.font: self.font]) let readMoreAttributed = NSMutableAttributedString(string: moreText, attributes: [NSAttributedString.Key.font: moreTextFont, NSAttributedString.Key.foregroundColor: moreTextColor]) answerAttributed.append(readMoreAttributed) self.attributedText = answerAttributed } } var visibleTextLength: Int { let font: UIFont = self.font let mode: NSLineBreakMode = self.lineBreakMode let labelWidth: CGFloat = self.frame.size.width let labelHeight: CGFloat = self.frame.size.height let sizeConstraint = CGSize(width: labelWidth, height: CGFloat.greatestFiniteMagnitude) if let myText = self.text { let attributes: [AnyHashable: Any] = [NSAttributedString.Key.font: font] let attributedText = NSAttributedString(string: myText, attributes: attributes as? [NSAttributedString.Key : Any]) let boundingRect: CGRect = attributedText.boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, context: nil) if boundingRect.size.height > labelHeight { var index: Int = 0 var prev: Int = 0 let characterSet = CharacterSet.whitespacesAndNewlines repeat { prev = index if mode == NSLineBreakMode.byCharWrapping { index += 1 } else { index = (myText as NSString).rangeOfCharacter(from: characterSet, options: [], range: NSRange(location: index + 1, length: myText.count - index - 1)).location } } while index != NSNotFound && index < myText.count && (myText as NSString).substring(to: index).boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, attributes: attributes as? [NSAttributedString.Key : Any], context: nil).size.height <= labelHeight return prev } } if self.text == nil { return 0 } else { return self.text!.count } } }

将UILabel的自定义类设置为ExpandableLabel并设置所需的行数和折叠文本：

ExpandableLable

您可能需要设置expandableLabel.numberOfLines = 5 expandableLabel.collapsedAttributedLink = NSAttributedString(string: "more") expandableLabel.ellipsis = NSAttributedString(string: "...") // update label expand or collapse state expandableLabel.collapsed = true以便在触摸链接时收到通知。

Answer 9

我的解决方案是，我在delegate的右下方创建了一个UIButton（名称阅读更多）。之后，我检查UILabel被截断或不显示或隐藏UILabel

UIButton

=== Swift 3版本

CGSize sizeOfText = [self.label.text boundingRectWithSize: CGSizeMake(self.label.intrinsicContentSize.width, CGFLOAT_MAX)
                                                 options: (NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                              attributes: [NSDictionary dictionaryWithObject:self.label.font forKey:NSFontAttributeName] context: nil].size;

if (self.label.intrinsicContentSize.height < ceilf(sizeOfText.height)) {
    // label is truncated
    self.readmoreButton.hidden = NO; // show Read more button
}else{
    self.readmoreButton.hidden = YES;
}

添加此扩展：

let textheight = self.label.text?.height(withConstrainedWidth: self.label.frame.width, font: self.label.font)
    if self.label.intrinsicContentSize.height < textheight! {
        self.readmoreButton.isHidden = false
    }else{
        self.readmoreButton.isHidden = true
    }

}

希望这有帮助

Answer 10

使用方法extension String { func height(withConstrainedWidth width: CGFloat, font: UIFont) -> CGFloat { let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude) let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil) return boundingBox.height }并将您的字体作为- boundingRectWithSize:options:attributes:context:的NSFontAttributeName键传递将为您提供所需的正确矩形。

从那里你需要检查它是否大于你的标签边界减去偏移量。只有在是的情况下，您需要修剪文本并在结尾处显示NSAttributedString。

Answer 11

此方法对于showless和showAll有向上箭头图像非常有用：在标签上添加tapgesture

Read More

Answer 12

  viewcontroller.h

  @property (nonatomic,assign) BOOL isReadable; 

  viewcontrollr.m

  #pragma mark :- Tap Gesture View All
  -(void)readMoreDidClickedGesture :(UITapGestureRecognizer 
    *)objTapGesture{

     UILabel * lblDesc = (UILabel *)[objTapGesture view];
     NSLog(@"%@",lblDesc.text);
     if (self.isReadable == false) {
     [self setIsReadable:YES];
     lblDesc.text = readmoreText;
     readMoreHeight = [self getLabelHeight:lblDesc];
     }
     else{
      readMoreHeight = 30.0;
      [self setIsReadable:NO];
      }  
  }



 - (void)addReadMoreStringToUILabel:(UILabel*)label isReaded:(BOOL)isReaded
 {

  NSString *readMoreText = (isReaded == false) ? @"...Show All  " : 
   @"Show Less  ";
  NSInteger lengthForString = label.text.length;
  if (lengthForString >= 30)
  {
    NSInteger lengthForVisibleString = [self getLabelHeight:label];//[self fitString:label.text intoLabel:label];
    NSMutableString *mutableString = [[NSMutableString alloc] initWithString:label.text];
    readmoreText = mutableString;
    NSString *trimmedString = [mutableString stringByReplacingCharactersInRange:NSMakeRange(lengthForVisibleString, (label.text.length - lengthForVisibleString)) withString:@""];
    NSInteger readMoreLength = readMoreText.length;
    NSString *trimmedForReadMore = [trimmedString stringByReplacingCharactersInRange:NSMakeRange((trimmedString.length - readMoreLength), readMoreLength) withString:@""];
    NSMutableAttributedString *answerAttributed = [[NSMutableAttributedString alloc] initWithString:trimmedForReadMore attributes:@{
                                                                                                                                    NSFontAttributeName : label.font
                                                                                                                                    }];


    NSMutableAttributedString *readMoreAttributed = [[NSMutableAttributedString alloc] initWithString:readMoreText attributes:@{
                                                                                                                                NSFontAttributeName :label.font,                              NSForegroundColorAttributeName :[UIColor orangeColor]
                                                                                                                                }];
    if (isReaded == false){
        [readMoreAttributed addAttribute:NSUnderlineStyleAttributeName
                             value:@(NSUnderlineStyleSingle)
                             range:NSMakeRange(3, 8)];

        NSTextAttachment *textAttachment = [[NSTextAttachment alloc] init];
        UIImageView *imgDown = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 25, 25)];
        imgDown.image = [UIImage imageNamed:@"searchFilterArrow1"];
        imgDown.image = [imgDown.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
        [imgDown setTintColor:[UIColor orangeColor]];

        textAttachment.image = imgDown.image;

        NSAttributedString *attrStringWithImage = [NSAttributedString attributedStringWithAttachment:textAttachment];

        [readMoreAttributed replaceCharactersInRange:NSMakeRange(12, 1) withAttributedString:attrStringWithImage];
    }
    else{
        [readMoreAttributed addAttribute:NSUnderlineStyleAttributeName
                                   value:@(NSUnderlineStyleSingle)
                                   range:NSMakeRange(1, 9)];
        NSTextAttachment *textAttachment = [[NSTextAttachment alloc] init];
        UIImageView *imgup = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 25, 25)];
        imgup.image = [UIImage imageNamed:@"searchFilterArrow2"];
        imgup.image = [imgup.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
        [imgup setTintColor:[UIColor orangeColor]];

        textAttachment.image = imgup.image;

        NSAttributedString *attrStringWithImage = [NSAttributedString attributedStringWithAttachment:textAttachment];

        [readMoreAttributed replaceCharactersInRange:NSMakeRange(11, 1) withAttributedString:attrStringWithImage];
    }

    [answerAttributed appendAttributedString:readMoreAttributed];
    label.attributedText = answerAttributed;

    UITapGestureRecognizer *readMoreGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(readMoreDidClickedGesture:)];
    readMoreGesture.numberOfTapsRequired = 1;
    [label addGestureRecognizer:readMoreGesture];

    label.userInteractionEnabled = YES;
}
else {

    NSLog(@"No need for 'Read More'...");

}
}

func updateData(_ label: UILabel) {
    self.headerLabel.text = detailViewModel.firstTitle
    self.detailLabel.text = detailViewModel.firstContent

    headerTitle = detailViewModel.firstTitle
    detailTitle = detailViewModel.firstContent

    DispatchQueue.main.async {
        let readMoreText = "...View More"
        let stringColor: UIColor = UIColor.blue
        let attributes = [NSForegroundColorAttributeName: stringColor]

        let numberOfLines = self.detailLabel.numberOfVisibleLines

        if numberOfLines > 2 {

            let lengthForVisibleString: Int = self.fit( self.detailLabel.text, into: self.detailLabel)
            let mutableString = self.detailLabel.text ?? ""
            let trimmedString = (mutableString as NSString).replacingCharacters(in: NSRange(location: lengthForVisibleString, length: (self.detailLabel?.text?.count ?? 0) - lengthForVisibleString), with: "")
            let readMoreLength: Int = readMoreText.count
            let trimmedForReadMore = (trimmedString as NSString).replacingCharacters(in: NSRange(location: trimmedString.count - readMoreLength, length: readMoreLength), with: "")
            let answerAttributed = NSMutableAttributedString(string: trimmedForReadMore, attributes: [NSFontAttributeName: self.detailLabel.font])

            let readMoreAttributed = NSMutableAttributedString(string: readMoreText, attributes: attributes)
            answerAttributed.append(readMoreAttributed)
            self.detailLabel.attributedText = answerAttributed


            let readMoreGesture = UITapGestureRecognizer(target: self, action:#selector(FundDetailsTableViewCell.showViewMore(_:)))
            readMoreGesture.numberOfTapsRequired = 1
            self.detailLabel.addGestureRecognizer(readMoreGesture)
            self.detailLabel.isUserInteractionEnabled = true
        }
    }
}

func fit(_ string: String?, into label: UILabel?) -> Int {
    guard let stringObjc = string as NSString? else {
        return 0
    }
    let font: UIFont = label?.font ?? UIFont.systemFont(ofSize: 14.0)
    let mode: NSLineBreakMode? = label?.lineBreakMode
    let labelWidth: CGFloat? = label?.frame.size.width
    let labelHeight: CGFloat? = label?.frame.size.height
    let sizeConstraint = CGSize(width: labelWidth ?? 0.0, height: CGFloat.greatestFiniteMagnitude)
    let attributes = [NSFontAttributeName: font]

    let device = UIDevice.current
    let iosVersion = Double(device.systemVersion) ?? 0

    if iosVersion > 7 {
        let attributedText = NSAttributedString(string: string ?? "", attributes: attributes)
        let boundingRect: CGRect = attributedText.boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, context: nil)
        do {
            if boundingRect.size.height > (labelHeight ?? 0.0) {
                var index: Int = 0
                var prev: Int
                let characterSet = CharacterSet.whitespacesAndNewlines
                repeat {
                    prev = index
                    if mode == .byCharWrapping {
                        index += 1
                    } else {
                        index = Int((string as NSString?)?.rangeOfCharacter(from: characterSet, options: [], range: NSRange(location: index + 1, length: (string?.count ?? 0) - index - 1)).location ?? 0)
                    }
                } while index != NSNotFound && index < (string?.count ?? 0)
                    && (stringObjc.substring(to: index).boundingRect(with: sizeConstraint, options: .usesLineFragmentOrigin, attributes: attributes, context: nil).size.height) <= labelHeight!
                return prev;
            }
        }
    } else {
        if stringObjc.size(attributes: attributes).height > labelHeight! {
            var index: Int = 0
            var prev: Int
            let characterSet = CharacterSet.whitespacesAndNewlines
            repeat {
                prev = index
                if mode == .byCharWrapping {
                    index += 1
                } else {
                    index = stringObjc.rangeOfCharacter(from: characterSet, options: NSString.CompareOptions.caseInsensitive, range: NSRange(location: index + 1, length: stringObjc.length - index - 1)).location
                }

            } while index != NSNotFound && index < (string?.count)! && (stringObjc.substring(to: index) as NSString).size(attributes: attributes).height <= labelHeight!
            return prev

        }
    }
    return (string?.count)!
}

func showViewMore(_ sender: UITapGestureRecognizer) {

}

在UILabel的末尾添加“... Read More”

问题描述投票：9回答：11

11个回答

最新问题

在UILabel的末尾添加“... Read More”

问题描述 投票：9回答：11

11个回答

最新问题

问题描述投票：9回答：11