Question

对于iOS 7，Apple制作了Helvetica Thin / Light的特殊修改版本，它具有圆形句点和冒号：

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

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是否可以开发具有圆形冒号和句号的特殊修改版本的应用程序？

编辑：原来这些圆形冒号和句号不是由Apple自定义设计的，它们是“字符替换”，您可以在自己喜欢的字体字形查看器中看到它们。

Answer 1

这是怎么做的。即使阅读文档，也很不清楚。

首先，您必须获得字体的特征，这将为您提供在UIFontDescriptorFeatureSettingsAttribute中使用的常量。我从this post得到了我的。

这为您提供了功能类型标识符键，以及它们的值选项，即功能选择器标识符键。

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

然后通过添加到描述符来创建字体描述符 - 这样您就可以通过UIFont指定字体名称和族：

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”仅表示我们没有将其从原始大小32缩放。

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

Answer 2

为了将来的读者，要看到字体特征数组，在Objective-C中它是：

@import CoreText;

和

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

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

对于产生的HelveticaNeue-UltraLight：

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是“Character Alternatives”，值1是“Time Punctuation”。

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的新动态类型系统访问这些功能。 http://tirania.org/monomac/archive/2013/Sep-25.html

是否可以在应用程序中使用iOS 7的修改过的Helvetica？

3 个答案: