Question

我收到了错误......

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

......当我尝试使用时......

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不再支持此方法了，还是我搞砸了语法？

Answer 1

初始化程序期望命名参数。

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
    }
}

注意：String可以投射到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
    }
}

-

<强>已更新

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

或者你可以把它转换成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

最新的Swift

 <!DOCTYPE html>
    <html>
    <head>
        <base href="http://demos.telerik.com/kendo-ui/dropdownlist/angular">
        <style>html { font-size: 14px; font-family: Arial, Helvetica, sans-serif; }</style>
        <title></title>
        <link rel="stylesheet" href="https://kendo.cdn.telerik.com/2017.1.118/styles/kendo.common.min.css" />
        <link rel="stylesheet" href="https://kendo.cdn.telerik.com/2017.1.118/styles/kendo.blueopal.min.css" />
        <link rel="stylesheet" href="https://kendo.cdn.telerik.com/2017.1.118/styles/kendo.blueopal.mobile.min.css" />

        <script src="https://kendo.cdn.telerik.com/2017.1.118/js/jquery.min.js"></script>
        <script src="https://kendo.cdn.telerik.com/2017.1.118/js/angular.min.js"></script>
        <script src="https://kendo.cdn.telerik.com/2017.1.118/js/kendo.all.min.js"></script>
    </head>
    <body>
    <div id="example" ng-app="KendoDemos">
        <div class="demo-section k-content" ng-controller="MyCtrl">
        <h4>Static data</h4>
        <select kendo-drop-down-list="mydropdown">
          <option>Albania</option>
          <option>Andorra</option>
          <option>Armenia</option>
          <option>Austria</option>
        </select>
    </div>
    </div>
    <script>
       var app = angular.module("KendoDemos", [ "kendo.directives" ])
          .controller("MyCtrl", function($scope){  
              $scope.$on("kendoWidgetCreated", function(event, widget){
                if (widget === $scope.mydropdown) {
                  widget.wrapper.on("focus", $scope.onFocus);
                  widget.wrapper.on("blur", $scope.onBlur);
                }
              });

            $scope.onFocus = function(){
                console.log("Kendo DropDownList focused!");
            };

            $scope.onBlur = function(){
                console.log("Kendo DropDownList blured!");
            };
          });

    </script>

Answer 4

最新的斯威夫特：

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

您可以使用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

Swift 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

最新的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

快速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
}

}

NSString boundingRectWithSize：options：attributes：context：在Swift中不可用？

8 个答案: