如何使用Swift制作子弹列表？

Question

所以我想用swift和xcode制作这样的东西:

从阵列中获取每个点的位置.我想到的是创建一个UILabel并创建一个遍历数组的for循环,并在每次迭代中添加到标签\ u {2022} +内容.我知道\ u {2022}是unicode中的点,问题是我需要一种方法将列表分成两列,如图所示,并使点点颜色为黄色.如果我按照上面描述的方式以编程方式添加点,则无法完成,因为默认颜色为黑色.由于点的数量与数组内容不同,例如,如果数组的大小为3,那么只有3个点在左边显示2,而在右边一个我需要一种方法来满足这个要求,我想到的另一种方法是有两个表视图,占用屏幕的一半,并根据数组将这些元素添加到每个表视图.什么应该是这里的最佳实践,或者有一种方法可以在故事板中以依赖于数组的形式进行此操作.

Answer 1

我对上述解决方案不满意。所以这里有一个 Swifty 函数来获取项目符号列表：

func bulletPointList(strings: [String]) -> NSAttributedString {
    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.headIndent = 15
    paragraphStyle.minimumLineHeight = 22
    paragraphStyle.maximumLineHeight = 22
    paragraphStyle.tabStops = [NSTextTab(textAlignment: .left, location: 15)]

    let stringAttributes = [
        NSAttributedString.Key.font: regularSystem(size: 22),
        NSAttributedString.Key.foregroundColor: UIColor.black,
        NSAttributedString.Key.paragraphStyle: paragraphStyle
    ]

    let string = strings.map({ "•\t\($0)" }).joined(separator: "\n")

    return NSAttributedString(string: string,
                              attributes: stringAttributes)
}

这就是你如何使用它：

label.numberOfLines = 0
label.attributedText = bulletPointList(strings: ["Foo", "Bar", "Lol"])

Answer 2

在列的视图中使用2个标签.两个标签都是多线的

class Helper {

    static func bulletedList(strings:[String], textColor:UIColor, font:UIFont, bulletColor:UIColor, bulletSize:BulletSize) -> NSAttributedString {
        let textAttributesDictionary = [NSFontAttributeName : font, NSForegroundColorAttributeName:textColor]

        let bulletAttributesDictionary = [NSFontAttributeName : font.withSize(bulletSize.rawValue), NSForegroundColorAttributeName:bulletColor]
        let fullAttributedString = NSMutableAttributedString.init()

        for string: String in strings
        {
            let bulletPoint: String = "\u{2022}"
            let formattedString: String = "\(bulletPoint) \(string)\n"
            let attributedString: NSMutableAttributedString = NSMutableAttributedString(string: formattedString)
            let paragraphStyle = createParagraphAttribute()

            attributedString.addAttributes([NSParagraphStyleAttributeName: paragraphStyle], range: NSMakeRange(0, attributedString.length))
            attributedString.addAttributes(textAttributesDictionary, range: NSMakeRange(0, attributedString.length))

            let string:NSString = NSString(string: formattedString)
            let rangeForBullet:NSRange = string.range(of: bulletPoint)

            attributedString.addAttributes(bulletAttributesDictionary, range: rangeForBullet)
            fullAttributedString.append(attributedString)
        }
        return fullAttributedString
    }

    static func createParagraphAttribute() -> NSParagraphStyle {

        var paragraphStyle: NSMutableParagraphStyle
        paragraphStyle = NSParagraphStyle.default.mutableCopy() as! NSMutableParagraphStyle
        paragraphStyle.tabStops = [NSTextTab(textAlignment: .left, location: 15, options: NSDictionary() as! [String : AnyObject])]
        paragraphStyle.defaultTabInterval = 15
        paragraphStyle.firstLineHeadIndent = 0
        paragraphStyle.lineSpacing = 3
        paragraphStyle.headIndent = 10
        return paragraphStyle
    }
}

并简单地用于Helper.bulletedList创建您的弹出列表作为标签的归属文本

Answer 3

对于 Swift 5，你可以使用这个类：

class NSAttributedStringHelper {
    static func createBulletedList(fromStringArray strings: [String], font: UIFont? = nil) -> NSAttributedString {

        let fullAttributedString = NSMutableAttributedString()
        let attributesDictionary: [NSAttributedString.Key: Any]

        if font != nil {
            attributesDictionary = [NSAttributedString.Key.font: font!]
        } else {
            attributesDictionary = [NSAttributedString.Key: Any]()
        }

        for index in 0..<strings.count {
            let bulletPoint: String = "\u{2022}"
            var formattedString: String = "\(bulletPoint) \(strings[index])"

            if index < strings.count - 1 {
                formattedString = "\(formattedString)\n"
            }

            let attributedString: NSMutableAttributedString = NSMutableAttributedString(string: formattedString, attributes: attributesDictionary)
            let paragraphStyle = NSAttributedStringHelper.createParagraphAttribute()
   attributedString.addAttributes([NSAttributedString.Key.paragraphStyle: paragraphStyle], range: NSMakeRange(0, attributedString.length))
        fullAttributedString.append(attributedString)
       }

        return fullAttributedString
    }

    private static func createParagraphAttribute() -> NSParagraphStyle {
        let paragraphStyle: NSMutableParagraphStyle = NSParagraphStyle.default.mutableCopy() as! NSMutableParagraphStyle
        paragraphStyle.tabStops = [NSTextTab(textAlignment: .left, location: 15, options: NSDictionary() as! [NSTextTab.OptionKey : Any])]
        paragraphStyle.defaultTabInterval = 15
        paragraphStyle.firstLineHeadIndent = 0
        paragraphStyle.headIndent = 11
        return paragraphStyle
    }
}

要使用它：

let stringArray = ["first row", "second row", "third row"]
label.attributedText = NSAttributedStringHelper.createBulletedList(fromStringArray: stringArray, font: UIFont.systemFont(ofSize: 15))