swift - 🫥 Swift isEmoji isEmojiPresentation

Question

为什么方法 isEmojiPresentation 返回 false？

"🫥".unicodeScalars.first?.properties.isEmoji //可选(false)

"🫥".unicodeScalars.first?.properties.isEmojiPresentation //可选(false)

文档

isEmoji - https://developer.apple.com/documentation/swift/unicode/scalar/properties-swift.struct/isemoji

isEmojiPresentation - https://developer.apple.com/documentation/swift/unicode/scalar/properties-swift.struct/isemojipresentation

UDP:

Answer 1

来自isEmoji documentation你发布了:

testing isEmoji alone on a single scalar is insufficient to determine if a unit of text is rendered as an emoji; a correct test requires inspecting multiple scalars in a Character.

因此，您可以使用以下代码来检查是否有表情符号呈现:

"🫥".unicodeScalars.contains(where: { $0.properties.isEmoji }) // true
"5".unicodeScalars.contains(where: { $0.properties.isEmoji }) // true, as expected (5️⃣)
"a".unicodeScalars.contains(where: { $0.properties.isEmoji }) // false

此代码用于检查默认情况下是否为表情符号呈现:

"🫥".unicodeScalars.contains(where: { $0.properties.isEmojiPresentation }) // true
"5".unicodeScalars.contains(where: { $0.properties.isEmojiPresentation }) // false
"a".unicodeScalars.contains(where: { $0.properties.isEmojiPresentation }) // false

这里是为方便起见的扩展:

extension Character {
    var hasEmojiPresentation: Bool {
        unicodeScalars.contains(where: { $0.properties.isEmoji })
    }

    var hasEmojiPresentationAsDefault: Bool {
        unicodeScalars.contains(where: { $0.properties.isEmojiPresentation })
    }
}

用法:

Character("🫥").hasEmojiPresentation // true
Character("🫥").hasEmojiPresentationAsDefault // true

Character("5").hasEmojiPresentation // true
Character("5").hasEmojiPresentationAsDefault // false

Character("a").hasEmojiPresentation // false
Character("a").hasEmojiPresentationAsDefault // false

注意:结果可能因使用的 Xcode 版本而异，因为它们包含不同的表情符号集。