是否可以在应用程序中使用iOS 7的修改版Helvetica？

Question

对于iOS 7，Apple制作了特殊的Helvetica Thin / Light修改版，该版本具有圆角和冒号：

与在Xcode中使用Helvetica-Neue Thin或Helvetica-Neue Light进行比较：

是否可以使用带有修改后的冒号和句号的特殊修改版来开发应用程序？

编辑 ：原来这些圆形冒号和句点不是Apple定制设计的，它们是“字符替代”，您可以在自己喜欢的字体字形查看器中看到它们。

Answer 1

这是操作方法。 即使阅读文档，也不清楚。

首先，您必须获取字体的特征，这将为您提供要在UIFontDescriptorFeatureSettingsAttribute使用的UIFontDescriptorFeatureSettingsAttribute 。 我从这个职位上得到了我。

这为您提供了特征类型标识符键，以及它们的值选项，特征选择器标识符键。

NSArray *timerDisplaySettings = @[
                                      @{ UIFontFeatureTypeIdentifierKey: @(6),
                                        UIFontFeatureSelectorIdentifierKey: @(1)
                                     },
                                      @{ UIFontFeatureTypeIdentifierKey: @(17),
                                        UIFontFeatureSelectorIdentifierKey: @(1)
                                        }];

然后通过添加一个描述符来创建字体描述符-这样，您可以通过UIFont指定字体名称和字体：

UIFont *font = [UIFont fontWithName:@"HelveticaNeue-UltraLight" size:32];

UIFontDescriptor *originalDescriptor = [font fontDescriptor];
UIFontDescriptor *timerDescriptor =[originalDescriptor fontDescriptorByAddingAttributes: @{ UIFontDescriptorFeatureSettingsAttribute: timerDisplaySettings }];

然后，关闭循环并使用描述符创建字体。 （大小“ 0.0”仅表示我们并未将其从原始大小32缩放。

UIFont *timerFont = [UIFont fontWithDescriptor: timerDescriptor size:0.0];

Answer 2

为了将来的读者，在Objective-C中查看字体特征数组是：

@import CoreText;

和

- (void)fontFeatures:(UIFont *)font {
    NSArray *features = CFBridgingRelease(CTFontCopyFeatures((__bridge CTFontRef)font));

    if (features) {
        NSLog(@"%@: %@", font.fontName, features);
    }
}

对于HelveticaNeue-UltraLight ，它产生：

HelveticaNeue-UltraLight: (
        {
        CTFeatureTypeIdentifier = 1;
        CTFeatureTypeName = Ligatures;
        CTFeatureTypeNameID = 258;
        CTFeatureTypeSelectors =         (
                        {
                CTFeatureSelectorDefault = 1;
                CTFeatureSelectorIdentifier = 2;
                CTFeatureSelectorName = "Common Ligatures";
                CTFeatureSelectorNameID = 259;
            }
        );
    },
        {
        CTFeatureTypeExclusive = 1;
        CTFeatureTypeIdentifier = 6;
        CTFeatureTypeName = "Number Spacing";
        CTFeatureTypeNameID = 262;
        CTFeatureTypeSelectors =         (
                        {
                CTFeatureSelectorDefault = 1;
                CTFeatureSelectorIdentifier = 0;
                CTFeatureSelectorName = "No Change";
                CTFeatureSelectorNameID = 264;
            },
                        {
                CTFeatureSelectorIdentifier = 1;
                CTFeatureSelectorName = "Proportional Numbers";
                CTFeatureSelectorNameID = 263;
            }
        );
    },
        {
        CTFeatureTypeExclusive = 1;
        CTFeatureTypeIdentifier = 17;
        CTFeatureTypeName = "Character Alternatives";
        CTFeatureTypeNameID = 265;
        CTFeatureTypeSelectors =         (
                        {
                CTFeatureSelectorDefault = 1;
                CTFeatureSelectorIdentifier = 0;
                CTFeatureSelectorName = "No Change";
                CTFeatureSelectorNameID = 264;
            },
                        {
                CTFeatureSelectorIdentifier = 1;
                CTFeatureSelectorName = "Time Punctuation";
                CTFeatureSelectorNameID = 266;
            },
                        {
                CTFeatureSelectorIdentifier = 2;
                CTFeatureSelectorName = "Compass Punctuation";
                CTFeatureSelectorNameID = 267;
            },
                        {
                CTFeatureSelectorIdentifier = 3;
                CTFeatureSelectorName = "Weather Punctuation";
                CTFeatureSelectorNameID = 268;
            },
                        {
                CTFeatureSelectorIdentifier = 4;
                CTFeatureSelectorName = "Round Lowercase Punctuation";
                CTFeatureSelectorNameID = 269;
            }
        );
    }
)

因此，在iOS 8中，对于HelveticaNeue-UltraLight ，键17为“字符替代”，值1为“时间标点”。

---

要在Swift中查看这些功能，它是：

import CoreText

和

func fontFeatures(font: UIFont) {
    if let features = CTFontCopyFeatures(font) as NSArray! {
        println("\(font.fontName): \(features)")
    }
}

Answer 3

是的，您可以通过iOS 7的新Dynamic Type系统访问这些功能。 http://tirania.org/monomac/archive/2013/Sep-25.html