I am trying to make a simple Coffee Calculator. I need to display the amount of coffee in grams. The "g" symbol for grams needs to be attached to my UILabel that I am using to display the amount. The numbers in the UILabel are changing dynamically with user input just fine, but I need to add a lower case "g" on the end of the string that is formatted differently from the updating numbers. The "g" needs to be attached to the numbers so that as the number size and position changes, the "g" "moves" with the numbers. I'm sure this problem has been solved before so a link in the right direction would be helpful as I've googled my little heart out.

I've searched through the documentation for an attributed string and I even downloded an "Attributed String Creator" from the app store, but the resulting code is in Objective-C and I am using Swift. What would be awesome, and probably helpful to other developers learning this language, is a clear example of creating a custom font with custom attributes using an attributed string in Swift. The documentation for this is very confusing as there is not a very clear path on how to do so. My plan is to create the attributed string and add it to the end of my coffeeAmount string.

var coffeeAmount: String = calculatedCoffee + attributedText

其中calculatedCoffee是一个Int转换为字符串和“attributedText”是小写的“g”与自定义字体,我试图创建。也许我做错了。任何帮助都是感激的!


当前回答

Objective-C 2.0示例:

myUILabel.text = @"€ 60,00";
NSMutableAttributedString *amountText = [[NSMutableAttributedString alloc] initWithString:myUILabel.text];

//Add attributes you are looking for
NSDictionary *dictionaryOfAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                        [UIFont systemFontOfSize:12],NSFontAttributeName,
                                        [UIColor grayColor],NSForegroundColorAttributeName,
                                        nil];

//Will gray color and resize the € symbol
[amountText setAttributes:dictionaryOfAttributes range:NSMakeRange(0, 1)];
myUILabel.attributedText = amountText;

其他回答

Swift: xcode 6.1

    let font:UIFont? = UIFont(name: "Arial", size: 12.0)

    let attrString = NSAttributedString(
        string: titleData,
        attributes: NSDictionary(
            object: font!,
            forKey: NSFontAttributeName))

细节

Swift 5.2, Xcode 11.4 (11E146)

解决方案

protocol AttributedStringComponent {
    var text: String { get }
    func getAttributes() -> [NSAttributedString.Key: Any]?
}

// MARK: String extensions

extension String: AttributedStringComponent {
    var text: String { self }
    func getAttributes() -> [NSAttributedString.Key: Any]? { return nil }
}

extension String {
    func toAttributed(with attributes: [NSAttributedString.Key: Any]?) -> NSAttributedString {
        .init(string: self, attributes: attributes)
    }
}

// MARK: NSAttributedString extensions

extension NSAttributedString: AttributedStringComponent {
    var text: String { string }

    func getAttributes() -> [Key: Any]? {
        if string.isEmpty { return nil }
        var range = NSRange(location: 0, length: string.count)
        return attributes(at: 0, effectiveRange: &range)
    }
}

extension NSAttributedString {

    convenience init?(from attributedStringComponents: [AttributedStringComponent],
                      defaultAttributes: [NSAttributedString.Key: Any],
                      joinedSeparator: String = " ") {
        switch attributedStringComponents.count {
        case 0: return nil
        default:
            var joinedString = ""
            typealias SttributedStringComponentDescriptor = ([NSAttributedString.Key: Any], NSRange)
            let sttributedStringComponents = attributedStringComponents.enumerated().flatMap { (index, component) -> [SttributedStringComponentDescriptor] in
                var components = [SttributedStringComponentDescriptor]()
                if index != 0 {
                    components.append((defaultAttributes,
                                       NSRange(location: joinedString.count, length: joinedSeparator.count)))
                    joinedString += joinedSeparator
                }
                components.append((component.getAttributes() ?? defaultAttributes,
                                   NSRange(location: joinedString.count, length: component.text.count)))
                joinedString += component.text
                return components
            }

            let attributedString = NSMutableAttributedString(string: joinedString)
            sttributedStringComponents.forEach { attributedString.addAttributes($0, range: $1) }
            self.init(attributedString: attributedString)
        }
    }
}

使用

let defaultAttributes = [
    .font: UIFont.systemFont(ofSize: 16, weight: .regular),
    .foregroundColor: UIColor.blue
] as [NSAttributedString.Key : Any]

let marketingAttributes = [
    .font: UIFont.systemFont(ofSize: 20.0, weight: .bold),
    .foregroundColor: UIColor.black
] as [NSAttributedString.Key : Any]

let attributedStringComponents = [
    "pay for",
    NSAttributedString(string: "one",
                       attributes: marketingAttributes),
    "and get",
    "three!\n".toAttributed(with: marketingAttributes),
    "Only today!".toAttributed(with: [
        .font: UIFont.systemFont(ofSize: 16.0, weight: .bold),
        .foregroundColor: UIColor.red
    ])
] as [AttributedStringComponent]
let attributedText = NSAttributedString(from: attributedStringComponents, defaultAttributes: defaultAttributes)

完整的示例

不要忘记在这里粘贴解决方案代码

import UIKit

class ViewController: UIViewController {

    private weak var label: UILabel!
    override func viewDidLoad() {
        super.viewDidLoad()
        let label = UILabel(frame: .init(x: 40, y: 40, width: 300, height: 80))
        label.numberOfLines = 2
        view.addSubview(label)
        self.label = label

        let defaultAttributes = [
            .font: UIFont.systemFont(ofSize: 16, weight: .regular),
            .foregroundColor: UIColor.blue
        ] as [NSAttributedString.Key : Any]

        let marketingAttributes = [
            .font: UIFont.systemFont(ofSize: 20.0, weight: .bold),
            .foregroundColor: UIColor.black
        ] as [NSAttributedString.Key : Any]

        let attributedStringComponents = [
            "pay for",
            NSAttributedString(string: "one",
                               attributes: marketingAttributes),
            "and get",
            "three!\n".toAttributed(with: marketingAttributes),
            "Only today!".toAttributed(with: [
                .font: UIFont.systemFont(ofSize: 16.0, weight: .bold),
                .foregroundColor: UIColor.red
            ])
        ] as [AttributedStringComponent]
        label.attributedText = NSAttributedString(from: attributedStringComponents, defaultAttributes: defaultAttributes)
        label.textAlignment = .center
    }
}

结果

斯威夫特4:

let attributes = [NSAttributedStringKey.font: UIFont(name: "HelveticaNeue-Bold", size: 17)!, 
                  NSAttributedStringKey.foregroundColor: UIColor.white]

对我来说,上面的解决方案在设置特定的颜色或属性时不起作用。

这招确实管用:

let attributes = [
    NSFontAttributeName : UIFont(name: "Helvetica Neue", size: 12.0)!,
    NSUnderlineStyleAttributeName : 1,
    NSForegroundColorAttributeName : UIColor.darkGrayColor(),
    NSTextEffectAttributeName : NSTextEffectLetterpressStyle,
    NSStrokeWidthAttributeName : 3.0]

var atriString = NSAttributedString(string: "My Attributed String", attributes: attributes)

我创建了一个在线工具来解决你的问题!你可以编写字符串并以图形化的方式应用样式,该工具会给你objective-c和swift代码来生成字符串。

Also是开源的,所以请随意扩展它并发送pr。

变压器的工具

Github