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iOS 8和iOS 9的系统字体

uifont ios9 ios8 ios

Valentin Shamardin · 技术社区 · 9 年前

我想为我的应用程序同时支持iOS 8和iOS 9系统。也许还有iOS 7。正如我们所知,iOS 7和8的系统字体是Helvetica Neue。但在iOS 9系统中,字体是旧金山。如果您没有通过 [UIFont fontWithName:@"HelveticaNeue" size:15]; ,但使用 [UIFont systemFontOfSize:15]; ,您将自动获得适用于iOS 7和8的Helvetica和适用于iOS 9的San Francisco。这太棒了! 对于界面生成器的标签和按钮,您可以设置薄、超薄、中等等系统字体。这也很棒。但是,我如何以编程方式在代码中设置这些薄、超、中等系统字体? 我是否需要为iOS 9和以前的iOS创建一个带有分叉的类别?

4 回复 | 直到 9 年前

Antoine 9 年前

我已创建此扩展:

import Foundation
import UIKit

enum SystemFontWeight : String {
    case UltraLight = "HelveticaNeue-UltraLight"
    case Thin = "HelveticaNeue-Thin"
    case Light = "HelveticaNeue-Light"
    case Regular = "HelveticaNeue"
    case Medium = "HelveticaNeue-Medium"
    case Semibold = "Helvetica-Bold"
    case Bold = "HelveticaNeue-Bold"
    case Heavy = "HelveticaNeue-CondensedBold"
    case Black = "HelveticaNeue-CondensedBlack"

    var weightValue:CGFloat? {
        if #available(iOS 8.2, *) {
            switch self {
            case .UltraLight:
                return UIFontWeightUltraLight
            case .Thin:
                return UIFontWeightThin
            case .Light:
                return UIFontWeightLight
            case .Regular:
                return UIFontWeightRegular
            case .Medium:
                return UIFontWeightMedium
            case .Semibold:
                return UIFontWeightSemibold
            case .Bold:
                return UIFontWeightBold
            case .Heavy:
                return UIFontWeightHeavy
            case .Black:
                return UIFontWeightBlack
            }
        } else {
            return nil
        }
    }
}

extension UIFont {
    static func systemFontOfSize(fontSize:CGFloat, weight:SystemFontWeight) -> UIFont {
        if #available(iOS 8.2, *) {
            return UIFont.systemFontOfSize(fontSize, weight: weight.weightValue!)

        } else {
            // Fallback on earlier versions
            return UIFont(name: weight.rawValue, size: fontSize)!
        }
    }
}

这使得可以应用如下字体:

myLabel.font = UIFont.systemFontOfSize(14, weight: .Medium)

这将自动为iOS 8和iOS 9设置正确的字体。

Léo Natan 9 年前

使用 + systemFontOfSize:weight: 。适用于iOS 8及以上版本。

对于iOS 7,界面生成器设置将起作用,对于代码,您需要创建 UIFontDescriptor 具有适当的重量。

Valentin Shamardin 9 年前

谢谢@利奥·纳坦。但我想向复制粘贴爱好者展示一段代码片段。

UIFont* systemFont = [UIFont respondsToSelector:@selector(systemFontOfSize:weight:)] ? [UIFont systemFontOfSize:25 weight:UIFontWeightThin] : [UIFont  fontWithName:@"HelveticaNeue-Thin" size:25];

appleBoy21 8 年前

感谢@Antoine为swift发布了很棒的答案。以下是目标C,如果有人愿意的话,类似的答案。实现UIFont的类别

UIFont+Cat.m

#import "UIFont+Cat.h"

@implementation UIFont (Cat)

+ (UIFont *)systemFontWithSize:(CGFloat)fontSize weight:(CGFloat)weight {
    if ([UIFont respondsToSelector:@selector(systemFontOfSize:weight:)]) {
        return [UIFont systemFontOfSize:fontSize weight:weight];
    }

    NSString *fontName = @"HelveticaNeue";
    if (weight == UIFontWeightUltraLight) {
        fontName = @"HelveticaNeue-UltraLight";
    }
    else if (weight == UIFontWeightThin) {
        fontName = @"HelveticaNeue-Thin";
    }
    else if (weight == UIFontWeightLight) {
        fontName = @"HelveticaNeue-Light";
    }
    else if (weight == UIFontWeightRegular) {
        fontName = @"HelveticaNeue";
    }
    else if (weight == UIFontWeightMedium) {
        fontName = @"HelveticaNeue-Medium";
    }
    else if (weight == UIFontWeightSemibold) {
        fontName = @"Helvetica-Bold";
    }
    else if (weight == UIFontWeightBold) {
        fontName = @"HelveticaNeue-Bold";
    }
    else if (weight == UIFontWeightHeavy) {
        fontName = @"HelveticaNeue-CondensedBold";
    }
    else if (weight == UIFontWeightBlack) {
        fontName = @"HelveticaNeue-CondensedBlack";
    }

    return [UIFont fontWithName:fontName size:fontSize];
}

@end