NSString boundingRectWithSize:options:attributes:context:在Sw

Question

我得到错误…

Could not find an overload for 'init' that accepts the supplied arguments

…当我尝试使用…

extension UIFont {
  func sizeOfString (string: String, constrainedToWidth width: Double) -> CGSize {
    NSString(string).boundingRectWithSize(CGSize(width, DBL_MAX),
                                          options: NSStringDrawingOptions.UsesLineFragmentOrigin,
                                          attributes: [NSFontAttributeName: self],
                                          context: nil).size
  }
}

NSString不再支持这个方法了吗，还是我在语法上搞砸了?

Answer 1

初始化器期望有命名参数。

extension UIFont {
    func sizeOfString (string: String, constrainedToWidth width: Double) -> CGSize {
        return NSString(string: string).boundingRectWithSize(CGSize(width: width, height: DBL_MAX),
            options: NSStringDrawingOptions.UsesLineFragmentOrigin,
            attributes: [NSFontAttributeName: self],
            context: nil).size
    }
}

注:String s可铸为NSString s

extension UIFont {
    func sizeOfString (string: String, constrainedToWidth width: Double) -> CGSize {
        return (string as NSString).boundingRectWithSize(CGSize(width: width, height: DBL_MAX),
            options: NSStringDrawingOptions.UsesLineFragmentOrigin,
            attributes: [NSFontAttributeName: self],
            context: nil).size
    }
}

或

extension UIFont {
    func sizeOfString (string: NSString, constrainedToWidth width: Double) -> CGSize {
        return string.boundingRectWithSize(CGSize(width: width, height: DBL_MAX),
            options: NSStringDrawingOptions.UsesLineFragmentOrigin,
            attributes: [NSFontAttributeName: self],
            context: nil).size
    }
}

,

对于Swift 4语法

extension UIFont {
    func sizeOfString (string: String, constrainedToWidth width: Double) -> CGSize {
        return NSString(string: string).boundingRect(
            with: CGSize(width: width, height: .greatestFiniteMagnitude),
            options: .usesLineFragmentOrigin,
            attributes: [.font: self],
            context: nil).size
    }
}

Answer 2

或者你可以将它转换成NSString

if let ns_str:NSString = str as NSString? {
   let sizeOfString = ns_str.boundingRectWithSize(
                                 CGSizeMake(self.titleLabel.frame.size.width, CGFloat.infinity), 
                                 options: NSStringDrawingOptions.UsesLineFragmentOrigin, 
                                 attributes: [NSFontAttributeName: lbl.font], 
                                 context: nil).size
}

Answer 3

最新迅速

func sizeOfString (string: String, constrainedToHeight height: Double) -> CGSize {
    return NSString(string: string).boundingRect(with: CGSize(width: DBL_MAX, height: height),
                                                 options: NSStringDrawingOptions.usesLineFragmentOrigin,
                                                 attributes: [NSFontAttributeName: UIFont.systemFont(ofSize: 20)],
                                                 context: nil).size
}

Answer 4

最新Swift:

import UIKit
extension UIFont {
    func sizeOfString(string: String, constrainedToWidth width: Double) -> CGSize {
        return NSString(string: string).boundingRect(with: CGSize(width: width, height: .greatestFiniteMagnitude),
                                                             options: .usesLineFragmentOrigin,
                                                             attributes: [NSFontAttributeName: self],
                                                             context: nil).size
    }
}

Answer 5

你可以使用objective-c桥接

let lblRegisterlinkWidth: CGFloat = lblRegisterLink.text!._bridgeToObjectiveC().boundingRectWithSize(lblRegisterLink.frame.size, options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName : lblRegisterLink.font], context: nil).size.width

Answer 6

迅速4.1版本

extension UIFont {
    func sizeOfString (string: String, constrainedToWidth width: Double) -> CGSize {
        return NSString(string: string).boundingRect(with: CGSize(width: width, height: .greatestFiniteMagnitude), options: NSStringDrawingOptions.usesLineFragmentOrigin, attributes: [NSFontAttributeName: self], context: nil).size
    }
}

Answer 7

最新Swift 5:

extension UIFont {
    func size(OfString string: String, constrainedToWidth width: Double) -> CGSize {
        return NSString(string: string).boundingRect(with: CGSize(width: width, height: .greatestFiniteMagnitude),
                                                     options: .usesLineFragmentOrigin,
                                                     attributes: [.font: self],
                                                     context: nil).size
    }
}

Answer 8

Swift 5

extension String {
    func sizeOfString(maxWidth: CGFloat, font: UIFont) -> CGSize {
        let tmp = NSMutableAttributedString(string: self, attributes:[NSAttributedString.Key.font: font])
        let limitSize = CGSize(width: maxWidth, height: CGFloat(MAXFLOAT))
        let contentSize = tmp.boundingRect(with: limitSize, options: .usesLineFragmentOrigin, context: nil)
        return contentSize.size
    }
}