在Swift 3/iOS10中使用Dynamic Type和自定义字体的更好方法

Question

在Swift 3/iOS10中使用Dynamic Type和自定义字体的更好方法

iel*_*ani 9 fonts ios swift uifontdescriptor dynamic-type-feature

我试过两种方法:

方法1:

label.font = UIFont.preferredFont(forTextStyle: UIFontTextStyle.body)
label.adjustsFontForContentSizeCategory = true

Run Code Online (Sandbox Code Playgroud)

即使在"设置"中更改了首选文本大小,文本大小也会自动更改,即使在我返回应用程序之前,这也可以正常工作.但它只适用于系统字体(旧金山).

方法2:

要使用自定义字体,我添加了一个扩展名UIFontDescriptor:

//from this answer http://stackoverflow.com/a/35467158/2907715
extension UIFontDescriptor {

    private struct SubStruct {
        static var preferredFontName: String = "Avenir-medium"
    }

    static let fontSizeTable : NSDictionary = [
        UIFontTextStyle.headline: [
            UIContentSizeCategory.accessibilityExtraExtraExtraLarge: 23,
            UIContentSizeCategory.accessibilityExtraExtraLarge: 23,
            UIContentSizeCategory.accessibilityExtraLarge: 23,
            UIContentSizeCategory.accessibilityLarge: 23,
            UIContentSizeCategory.accessibilityMedium: 23,
            UIContentSizeCategory.extraExtraExtraLarge: 23,
            UIContentSizeCategory.extraExtraLarge: 21,
            UIContentSizeCategory.extraLarge: 19,
            UIContentSizeCategory.large: 17,
            UIContentSizeCategory.medium: 16,
            UIContentSizeCategory.small: 15,
            UIContentSizeCategory.extraSmall: 14
        ],
        UIFontTextStyle.subheadline: [
            UIContentSizeCategory.accessibilityExtraExtraExtraLarge: 21,
            UIContentSizeCategory.accessibilityExtraExtraLarge: 21,
            UIContentSizeCategory.accessibilityExtraLarge: 21,
            UIContentSizeCategory.accessibilityLarge: 21,
            UIContentSizeCategory.accessibilityMedium: 21,
            UIContentSizeCategory.extraExtraExtraLarge: 21,
            UIContentSizeCategory.extraExtraLarge: 19,
            UIContentSizeCategory.extraLarge: 17,
            UIContentSizeCategory.large: 15,
            UIContentSizeCategory.medium: 14,
            UIContentSizeCategory.small: 13,
            UIContentSizeCategory.extraSmall: 12
        ],
        UIFontTextStyle.body: [
            UIContentSizeCategory.accessibilityExtraExtraExtraLarge: 53,
            UIContentSizeCategory.accessibilityExtraExtraLarge: 47,
            UIContentSizeCategory.accessibilityExtraLarge: 40,
            UIContentSizeCategory.accessibilityLarge: 33,
            UIContentSizeCategory.accessibilityMedium: 28,
            UIContentSizeCategory.extraExtraExtraLarge: 23,
            UIContentSizeCategory.extraExtraLarge: 21,
            UIContentSizeCategory.extraLarge: 19,
            UIContentSizeCategory.large: 17,
            UIContentSizeCategory.medium: 16,
            UIContentSizeCategory.small: 15,
            UIContentSizeCategory.extraSmall: 14
        ],
        UIFontTextStyle.caption1: [
            UIContentSizeCategory.accessibilityExtraExtraExtraLarge: 18,
            UIContentSizeCategory.accessibilityExtraExtraLarge: 18,
            UIContentSizeCategory.accessibilityExtraLarge: 18,
            UIContentSizeCategory.accessibilityLarge: 18,
            UIContentSizeCategory.accessibilityMedium: 18,
            UIContentSizeCategory.extraExtraExtraLarge: 18,
            UIContentSizeCategory.extraExtraLarge: 16,
            UIContentSizeCategory.extraLarge: 14,
            UIContentSizeCategory.large: 12,
            UIContentSizeCategory.medium: 11,
            UIContentSizeCategory.small: 11,
            UIContentSizeCategory.extraSmall: 11
        ],
        UIFontTextStyle.caption2: [
            UIContentSizeCategory.accessibilityExtraExtraExtraLarge: 17,
            UIContentSizeCategory.accessibilityExtraExtraLarge: 17,
            UIContentSizeCategory.accessibilityExtraLarge: 17,
            UIContentSizeCategory.accessibilityLarge: 17,
            UIContentSizeCategory.accessibilityMedium: 17,
            UIContentSizeCategory.extraExtraExtraLarge: 17,
            UIContentSizeCategory.extraExtraLarge: 15,
            UIContentSizeCategory.extraLarge: 13,
            UIContentSizeCategory.large: 11,
            UIContentSizeCategory.medium: 11,
            UIContentSizeCategory.small: 11,
            UIContentSizeCategory.extraSmall: 11
        ],
        UIFontTextStyle.footnote: [
            UIContentSizeCategory.accessibilityExtraExtraExtraLarge: 19,
            UIContentSizeCategory.accessibilityExtraExtraLarge: 19,
            UIContentSizeCategory.accessibilityExtraLarge: 19,
            UIContentSizeCategory.accessibilityLarge: 19,
            UIContentSizeCategory.accessibilityMedium: 19,
            UIContentSizeCategory.extraExtraExtraLarge: 19,
            UIContentSizeCategory.extraExtraLarge: 17,
            UIContentSizeCategory.extraLarge: 15,
            UIContentSizeCategory.large: 13,
            UIContentSizeCategory.medium: 12,
            UIContentSizeCategory.small: 12,
            UIContentSizeCategory.extraSmall: 12
        ],
        ]

    final class func preferredDescriptor(textStyle: String) -> UIFontDescriptor {

        let contentSize = UIApplication.shared.preferredContentSizeCategory
        let style = fontSizeTable[textStyle] as! NSDictionary
        return UIFontDescriptor(name: SubStruct.preferredFontName, size: CGFloat((style[contentSize] as! NSNumber).floatValue))
    }

}

Run Code Online (Sandbox Code Playgroud)

并在viewDidLoad():

label.font = UIFont(descriptor: UIFontDescriptor.preferredDescriptor(textStyle: UIFontTextStyle.body.rawValue), size: 0)
NotificationCenter.default.addObserver(self, selector:#selector(self.userChangedTextSize(notification:)), name: NSNotification.Name.UIContentSizeCategoryDidChange, object: nil)

Run Code Online (Sandbox Code Playgroud)

这是userChangedTextSize功能:

func userChangedTextSize(notification: NSNotification) {
    label.font = UIFont(descriptor: UIFontDescriptor.preferredDescriptor(textStyle: UIFontTextStyle.body.rawValue), size: 0)
}

Run Code Online (Sandbox Code Playgroud)

此方法的问题是文本大小在用户返回应用程序之前不会更改,然后用户会看到旧文本大小更改为新大小,这是不理想的.

我可以充分利用这两个世界:自定义字体的大小会在后台自动更改吗？

Answer 1

Fre*_*orf 20

此方法的问题是文本大小在用户返回应用程序之前不会更改,然后用户会看到旧文本大小更改为新大小,这是不理想的.

我分享你的想法,这可能是一个更好的用户体验,但我想你有点过分思考它.

如果您查看系统提供的应用程序(例如联系人),您将清楚地看到在用户返回应用程序之前不会进行刷新.

顺便说一下,你可以为Swift 3重构一下你的代码:

extension UIFontDescriptor {

    private struct SubStruct {
        static var preferredFontName: String = "Avenir-medium"
    }

    static let fontSizeTable: [UIFontTextStyle: [UIContentSizeCategory: CGFloat]] = [
        .headline: [
            .accessibilityExtraExtraExtraLarge: 23,
            .accessibilityExtraExtraLarge: 23,
            .accessibilityExtraLarge: 23,
            .accessibilityLarge: 23,
            .accessibilityMedium: 23,
            .extraExtraExtraLarge: 23,
            .extraExtraLarge: 21,
            .extraLarge: 19,
            .large: 17,
            .medium: 16,
            .small: 15,
            .extraSmall: 14
        ],
        .subheadline: [
            .accessibilityExtraExtraExtraLarge: 21,
            .accessibilityExtraExtraLarge: 21,
            .accessibilityExtraLarge: 21,
            .accessibilityLarge: 21,
            .accessibilityMedium: 21,
            .extraExtraExtraLarge: 21,
            .extraExtraLarge: 19,
            .extraLarge: 17,
            .large: 15,
            .medium: 14,
            .small: 13,
            .extraSmall: 12
        ],
        .body: [
            .accessibilityExtraExtraExtraLarge: 53,
            .accessibilityExtraExtraLarge: 47,
            .accessibilityExtraLarge: 40,
            .accessibilityLarge: 33,
            .accessibilityMedium: 28,
            .extraExtraExtraLarge: 23,
            .extraExtraLarge: 21,
            .extraLarge: 19,
            .large: 17,
            .medium: 16,
            .small: 15,
            .extraSmall: 14
        ],
        .caption1: [
            .accessibilityExtraExtraExtraLarge: 18,
            .accessibilityExtraExtraLarge: 18,
            .accessibilityExtraLarge: 18,
            .accessibilityLarge: 18,
            .accessibilityMedium: 18,
            .extraExtraExtraLarge: 18,
            .extraExtraLarge: 16,
            .extraLarge: 14,
            .large: 12,
            .medium: 11,
            .small: 11,
            .extraSmall: 11
        ],
        .caption2: [
            .accessibilityExtraExtraExtraLarge: 17,
            .accessibilityExtraExtraLarge: 17,
            .accessibilityExtraLarge: 17,
            .accessibilityLarge: 17,
            .accessibilityMedium: 17,
            .extraExtraExtraLarge: 17,
            .extraExtraLarge: 15,
            .extraLarge: 13,
            .large: 11,
            .medium: 11,
            .small: 11,
            .extraSmall: 11
        ],
        .footnote: [
            .accessibilityExtraExtraExtraLarge: 19,
            .accessibilityExtraExtraLarge: 19,
            .accessibilityExtraLarge: 19,
            .accessibilityLarge: 19,
            .accessibilityMedium: 19,
            .extraExtraExtraLarge: 19,
            .extraExtraLarge: 17,
            .extraLarge: 15,
            .large: 13,
            .medium: 12,
            .small: 12,
            .extraSmall: 12
        ]
    ]

    final class func preferredDescriptor(textStyle: UIFontTextStyle) -> UIFontDescriptor {
        let contentSize = UIApplication.shared.preferredContentSizeCategory
        let style = fontSizeTable[textStyle]!
        return UIFontDescriptor(name: SubStruct.preferredFontName, size: style[contentSize]!)
    }
}

Run Code Online (Sandbox Code Playgroud)

无需投射NSDictionary或间接NSNumber获得floatValue.

这样,您的呼叫站点可以使用以下更易读的代码:

func userChangedTextSize(notification: NSNotification) {
    label.font = UIFont(descriptor: .preferredDescriptor(textStyle: .body), size: 0)

}

Run Code Online (Sandbox Code Playgroud)

编辑:当我正在进行同样的工作时,我将上述(在常见的解决方案中)改进为更容易的方式.

import UIKIt

extension UIFont {

    private struct CustomFont {
        static var fontFamily = "Avenir"
    }

    /// Returns a bold version of `self`
    public var bolded: UIFont {
        return fontDescriptor.withSymbolicTraits(.traitBold)
            .map { UIFont(descriptor: $0, size: 0) } ?? self
    }

    /// Returns an italic version of `self`
    public var italicized: UIFont {
        return fontDescriptor.withSymbolicTraits(.traitItalic)
            .map { UIFont(descriptor: $0, size: 0) } ?? self
    }

    /// Returns a scaled version of `self`
    func scaled(scaleFactor: CGFloat) -> UIFont {
        let newDescriptor = fontDescriptor.withSize(fontDescriptor.pointSize * scaleFactor)
        return UIFont(descriptor: newDescriptor, size: 0)
    }

    class func preferredCustomFont(forTextStyle textStyle: UIFontTextStyle) -> UIFont {
        // we are using the UIFontDescriptor which is less expensive than creating an intermediate UIFont
        let systemFontDescriptor = UIFontDescriptor.preferredFontDescriptor(withTextStyle: textStyle)

        let customFontDescriptor = UIFontDescriptor.init(fontAttributes: [
            UIFontDescriptorFamilyAttribute: CustomFont.fontFamily,
            UIFontDescriptorSizeAttribute: systemFontDescriptor.pointSize // use the font size of the default dynamic font
        ])

        // return font of new family with same size as the preferred system font
        return UIFont(descriptor: customFontDescriptor, size: 0)
    }

}

Run Code Online (Sandbox Code Playgroud)

用法

func userChangedTextSize(notification: NSNotification) {
    label.font = UIFont.preferredCustomFont(forTextStyle: .headline)
    // or in Bold / Italic:
    // label.font = UIFont.preferredCustomFont(forTextStyle: .headline).bolded
    // label.font = UIFont.preferredCustomFont(forTextStyle: .headline).italicized
}

Run Code Online (Sandbox Code Playgroud)

@ FrederikA.Winkelsdorf我想出了如何解决这个问题，我不得不使用traitCollectionDidChange (2认同)

归档时间：	8 年，11 月前
查看次数：	6346 次
最近记录：	6 年，3 月前