如果您对蒙古语的细节不感兴趣，而只是想快速了解在Swift中使用和转换Unicode值，那么请跳至已接受答案的第一部分。背景我要为iOS应用程序中使用的传统蒙古语呈现Unicode文本。更好的长期解决方案是使用AAT智能字体来呈现此复杂脚本。（确实存在这样的字体，但是它们的许可证不允许修改和非个人使用。）但是，由于我从未制作过字体，更不用说AAT字体的所有渲染逻辑了，我只打算自己进行渲染。斯威夫特暂时。也许以后我可以学习制作智能字体。在外部，我将使用Unicode文本，但在内部（以显示为UITextView），我将Unicode转换为以哑字体（用Unicode PUA值编码）存储的单个字形。因此，我的渲染引擎需要将蒙古Unicode值（范围：U + 1820到U + 1842）转换为存储在PUA中的字形值（范围：U + E360到U + E5CF）。无论如何，这是我的计划，因为这是我过去在Java中所做的，但是也许我需要改变整体思维方式。例下图显示了使用两种不同形式的字母u（用红色）在蒙古语中写过su两次。（蒙古语是垂直书写的，字母像草书字母一样用英语连接。）在此处输入图片说明在Unicode中，这两个字符串将表示为var suForm1: String = "\u{1830}\u{1826}"var suForm2: String = "\u{1830}\u{1826}\u{180B}"suForm2Swift 将自由变体选择器（U + 180B）识别（正确）为在其前面String带有u（U + 1826）的单元。Swift将其视为单个字符，扩展的字素簇。但是，出于自己进行渲染的目的，我需要将u（U + 1826）和FVS1（U + 180B）区分为两个不同的UTF-16代码点。为了内部显示，我将上述Unicode字符串转换为以下呈现的字形字符串：suForm1 = "\u{E46F}\u{E3BA}" suForm2 = "\u{E46F}\u{E3BB}"题我一直在和Swift String和Character。关于它们有很多方便的事情，但是由于在我的特殊情况下，我只处理UTF-16代码单元，所以我想知道是否应该使用旧的NSString而不是Swift的代码String。我意识到我可以String.utf16用来获取UTF-16代码点，但是转换回String并不是很好。坚持使用String和Character还是应该使用NSString和更好unichar？
2 回答
素胚勾勒不出你
TA贡献1827条经验 获得超9个赞
为Swift 3更新
字符串和字符
对于几乎每个人都在谁访问了这个问题，未来String，并Character会为你的答案。
直接在代码中设置Unicode值：
var str: String = "I want to visit 北京, Москва, मुंबई, القاهرة, and 서울시. ?"
var character: Character = "?"
使用十六进制设置值
var str: String = "\u{61}\u{5927}\u{1F34E}\u{3C0}" // a大?π
var character: Character = "\u{65}\u{301}" // é = "e" + accent mark
请注意，Swift字符可以由多个Unicode代码点组成，但看起来像是一个字符。这称为扩展字素簇。
另请参阅此问题。
转换为Unicode值：
str.utf8
str.utf16
str.unicodeScalars // UTF-32
String(character).utf8
String(character).utf16
String(character).unicodeScalars
从Unicode十六进制值转换：
let hexValue: UInt32 = 0x1F34E
// convert hex value to UnicodeScalar
guard let scalarValue = UnicodeScalar(hexValue) else {
// early exit if hex does not form a valid unicode value
return
}
// convert UnicodeScalar to String
let myString = String(scalarValue) // ?
或者：
let hexValue: UInt32 = 0x1F34E
if let scalarValue = UnicodeScalar(hexValue) {
let myString = String(scalarValue)
}
其他一些例子
let value0: UInt8 = 0x61
let value1: UInt16 = 0x5927
let value2: UInt32 = 0x1F34E
let string0 = String(UnicodeScalar(value0)) // a
let string1 = String(UnicodeScalar(value1)) // 大
let string2 = String(UnicodeScalar(value2)) // ?
// convert hex array to String
let myHexArray = [0x43, 0x61, 0x74, 0x203C, 0x1F431] // an Int array
var myString = ""
for hexValue in myHexArray {
myString.append(UnicodeScalar(hexValue))
}
print(myString) // Cat‼?
请注意，对于UTF-8和UTF-16，转换并不总是那么容易。（请参阅UTF-8，UTF-16和UTF-32问题。）
NSString和unichar
也可能与工作NSString和unichar斯威夫特，但你应该明白，除非你是熟悉的语法转换为斯威夫特目标C和好，这将是很难找到良好的文档。
同样，unichar是一个UInt16数组，如上所述，从UInt16Unicode标量值的转换并不总是那么容易（即，将诸如emoji表情和其他字符的对象的替代对在上层代码平面中转换）。
自定义字符串结构
由于问题中提到的原因，我最终没有使用任何上述方法。相反，我编写了自己的字符串结构，该结构基本上是一个数组，UInt32用于保存Unicode标量值。
同样，这不是大多数人的解决方案。如果只需要扩展或扩展一点功能，请首先考虑使用扩展。StringCharacter
但是，如果确实需要专门处理Unicode标量值，则可以编写自定义结构。
优点是：
不需要类型（间不断切换String，Character，UnicodeScalar，UInt32做字符串操作时，等）。
完成Unicode操作后，最终的转换String很容易。
易于在需要时添加更多方法
简化了从Java或其他语言的代码转换
缺点是：
使代码的可移植性和其他Swift开发人员的可读性降低
没有像本机Swift类型那样经过充分测试和优化
它是您每次需要时都必须包含在项目中的另一个文件
您可以自己制作，但这是我的参考。最难的部分是使其变得可哈希化。
// This struct is an array of UInt32 to hold Unicode scalar values
// Version 3.4.0 (Swift 3 update)
struct ScalarString: Sequence, Hashable, CustomStringConvertible {
fileprivate var scalarArray: [UInt32] = []
init() {
// does anything need to go here?
}
init(_ character: UInt32) {
self.scalarArray.append(character)
}
init(_ charArray: [UInt32]) {
for c in charArray {
self.scalarArray.append(c)
}
}
init(_ string: String) {
for s in string.unicodeScalars {
self.scalarArray.append(s.value)
}
}
// Generator in order to conform to SequenceType protocol
// (to allow users to iterate as in `for myScalarValue in myScalarString` { ... })
func makeIterator() -> AnyIterator<UInt32> {
return AnyIterator(scalarArray.makeIterator())
}
// append
mutating func append(_ scalar: UInt32) {
self.scalarArray.append(scalar)
}
mutating func append(_ scalarString: ScalarString) {
for scalar in scalarString {
self.scalarArray.append(scalar)
}
}
mutating func append(_ string: String) {
for s in string.unicodeScalars {
self.scalarArray.append(s.value)
}
}
// charAt
func charAt(_ index: Int) -> UInt32 {
return self.scalarArray[index]
}
// clear
mutating func clear() {
self.scalarArray.removeAll(keepingCapacity: true)
}
// contains
func contains(_ character: UInt32) -> Bool {
for scalar in self.scalarArray {
if scalar == character {
return true
}
}
return false
}
// description (to implement Printable protocol)
var description: String {
return self.toString()
}
// endsWith
func endsWith() -> UInt32? {
return self.scalarArray.last
}
// indexOf
// returns first index of scalar string match
func indexOf(_ string: ScalarString) -> Int? {
if scalarArray.count < string.length {
return nil
}
for i in 0...(scalarArray.count - string.length) {
for j in 0..<string.length {
if string.charAt(j) != scalarArray[i + j] {
break // substring mismatch
}
if j == string.length - 1 {
return i
}
}
}
return nil
}
// insert
mutating func insert(_ scalar: UInt32, atIndex index: Int) {
self.scalarArray.insert(scalar, at: index)
}
mutating func insert(_ string: ScalarString, atIndex index: Int) {
var newIndex = index
for scalar in string {
self.scalarArray.insert(scalar, at: newIndex)
newIndex += 1
}
}
mutating func insert(_ string: String, atIndex index: Int) {
var newIndex = index
for scalar in string.unicodeScalars {
self.scalarArray.insert(scalar.value, at: newIndex)
newIndex += 1
}
}
// isEmpty
var isEmpty: Bool {
return self.scalarArray.count == 0
}
// hashValue (to implement Hashable protocol)
var hashValue: Int {
// DJB Hash Function
return self.scalarArray.reduce(5381) {
($0 << 5) &+ $0 &+ Int($1)
}
}
// length
var length: Int {
return self.scalarArray.count
}
// remove character
mutating func removeCharAt(_ index: Int) {
self.scalarArray.remove(at: index)
}
func removingAllInstancesOfChar(_ character: UInt32) -> ScalarString {
var returnString = ScalarString()
for scalar in self.scalarArray {
if scalar != character {
returnString.append(scalar)
}
}
return returnString
}
func removeRange(_ range: CountableRange<Int>) -> ScalarString? {
if range.lowerBound < 0 || range.upperBound > scalarArray.count {
return nil
}
var returnString = ScalarString()
for i in 0..<scalarArray.count {
if i < range.lowerBound || i >= range.upperBound {
returnString.append(scalarArray[i])
}
}
return returnString
}
// replace
func replace(_ character: UInt32, withChar replacementChar: UInt32) -> ScalarString {
var returnString = ScalarString()
for scalar in self.scalarArray {
if scalar == character {
returnString.append(replacementChar)
} else {
returnString.append(scalar)
}
}
return returnString
}
func replace(_ character: UInt32, withString replacementString: String) -> ScalarString {
var returnString = ScalarString()
for scalar in self.scalarArray {
if scalar == character {
returnString.append(replacementString)
} else {
returnString.append(scalar)
}
}
return returnString
}
func replaceRange(_ range: CountableRange<Int>, withString replacementString: ScalarString) -> ScalarString {
var returnString = ScalarString()
for i in 0..<scalarArray.count {
if i < range.lowerBound || i >= range.upperBound {
returnString.append(scalarArray[i])
} else if i == range.lowerBound {
returnString.append(replacementString)
}
}
return returnString
}
// set (an alternative to myScalarString = "some string")
mutating func set(_ string: String) {
self.scalarArray.removeAll(keepingCapacity: false)
for s in string.unicodeScalars {
self.scalarArray.append(s.value)
}
}
// split
func split(atChar splitChar: UInt32) -> [ScalarString] {
var partsArray: [ScalarString] = []
if self.scalarArray.count == 0 {
return partsArray
}
var part: ScalarString = ScalarString()
for scalar in self.scalarArray {
if scalar == splitChar {
partsArray.append(part)
part = ScalarString()
} else {
part.append(scalar)
}
}
partsArray.append(part)
return partsArray
}
// startsWith
func startsWith() -> UInt32? {
return self.scalarArray.first
}
// substring
func substring(_ startIndex: Int) -> ScalarString {
// from startIndex to end of string
var subArray: ScalarString = ScalarString()
for i in startIndex..<self.length {
subArray.append(self.scalarArray[i])
}
return subArray
}
func substring(_ startIndex: Int, _ endIndex: Int) -> ScalarString {
// (startIndex is inclusive, endIndex is exclusive)
var subArray: ScalarString = ScalarString()
for i in startIndex..<endIndex {
subArray.append(self.scalarArray[i])
}
return subArray
}
// toString
func toString() -> String {
var string: String = ""
for scalar in self.scalarArray {
if let validScalor = UnicodeScalar(scalar) {
string.append(Character(validScalor))
}
}
return string
}
// trim
// removes leading and trailing whitespace (space, tab, newline)
func trim() -> ScalarString {
//var returnString = ScalarString()
let space: UInt32 = 0x00000020
let tab: UInt32 = 0x00000009
let newline: UInt32 = 0x0000000A
var startIndex = self.scalarArray.count
var endIndex = 0
// leading whitespace
for i in 0..<self.scalarArray.count {
if self.scalarArray[i] != space &&
self.scalarArray[i] != tab &&
self.scalarArray[i] != newline {
startIndex = i
break
}
}
// trailing whitespace
for i in stride(from: (self.scalarArray.count - 1), through: 0, by: -1) {
if self.scalarArray[i] != space &&
self.scalarArray[i] != tab &&
self.scalarArray[i] != newline {
endIndex = i + 1
break
}
}
if endIndex <= startIndex {
return ScalarString()
}
return self.substring(startIndex, endIndex)
}
// values
func values() -> [UInt32] {
return self.scalarArray
}
}
func ==(left: ScalarString, right: ScalarString) -> Bool {
return left.scalarArray == right.scalarArray
}
func +(left: ScalarString, right: ScalarString) -> ScalarString {
var returnString = ScalarString()
for scalar in left.values() {
returnString.append(scalar)
}
for scalar in right.values() {
returnString.append(scalar)
}
return returnString
}
HUWWW
TA贡献1874条经验 获得超12个赞
//Swift 3.0
// This struct is an array of UInt32 to hold Unicode scalar values
struct ScalarString: Sequence, Hashable, CustomStringConvertible {
private var scalarArray: [UInt32] = []
init() {
// does anything need to go here?
}
init(_ character: UInt32) {
self.scalarArray.append(character)
}
init(_ charArray: [UInt32]) {
for c in charArray {
self.scalarArray.append(c)
}
}
init(_ string: String) {
for s in string.unicodeScalars {
self.scalarArray.append(s.value)
}
}
// Generator in order to conform to SequenceType protocol
// (to allow users to iterate as in `for myScalarValue in myScalarString` { ... })
//func generate() -> AnyIterator<UInt32> {
func makeIterator() -> AnyIterator<UInt32> {
let nextIndex = 0
return AnyIterator {
if (nextIndex > self.scalarArray.count-1) {
return nil
}
return self.scalarArray[nextIndex + 1]
}
}
// append
mutating func append(scalar: UInt32) {
self.scalarArray.append(scalar)
}
mutating func append(scalarString: ScalarString) {
for scalar in scalarString {
self.scalarArray.append(scalar)
}
}
mutating func append(string: String) {
for s in string.unicodeScalars {
self.scalarArray.append(s.value)
}
}
// charAt
func charAt(index: Int) -> UInt32 {
return self.scalarArray[index]
}
// clear
mutating func clear() {
self.scalarArray.removeAll(keepingCapacity: true)
}
// contains
func contains(character: UInt32) -> Bool {
for scalar in self.scalarArray {
if scalar == character {
return true
}
}
return false
}
// description (to implement Printable protocol)
var description: String {
var string: String = ""
for scalar in scalarArray {
string.append(String(describing: UnicodeScalar(scalar))) //.append(UnicodeScalar(scalar)!)
}
return string
}
// endsWith
func endsWith() -> UInt32? {
return self.scalarArray.last
}
// insert
mutating func insert(scalar: UInt32, atIndex index: Int) {
self.scalarArray.insert(scalar, at: index)
}
// isEmpty
var isEmpty: Bool {
get {
return self.scalarArray.count == 0
}
}
// hashValue (to implement Hashable protocol)
var hashValue: Int {
get {
// DJB Hash Function
var hash = 5381
for i in 0 ..< scalarArray.count {
hash = ((hash << 5) &+ hash) &+ Int(self.scalarArray[i])
}
/*
for i in 0..< self.scalarArray.count {
hash = ((hash << 5) &+ hash) &+ Int(self.scalarArray[i])
}
*/
return hash
}
}
// length
var length: Int {
get {
return self.scalarArray.count
}
}
// remove character
mutating func removeCharAt(index: Int) {
self.scalarArray.remove(at: index)
}
func removingAllInstancesOfChar(character: UInt32) -> ScalarString {
var returnString = ScalarString()
for scalar in self.scalarArray {
if scalar != character {
returnString.append(scalar: scalar) //.append(scalar)
}
}
return returnString
}
// replace
func replace(character: UInt32, withChar replacementChar: UInt32) -> ScalarString {
var returnString = ScalarString()
for scalar in self.scalarArray {
if scalar == character {
returnString.append(scalar: replacementChar) //.append(replacementChar)
} else {
returnString.append(scalar: scalar) //.append(scalar)
}
}
return returnString
}
// func replace(character: UInt32, withString replacementString: String) -> ScalarString {
func replace(character: UInt32, withString replacementString: ScalarString) -> ScalarString {
var returnString = ScalarString()
for scalar in self.scalarArray {
if scalar == character {
returnString.append(scalarString: replacementString) //.append(replacementString)
} else {
returnString.append(scalar: scalar) //.append(scalar)
}
}
return returnString
}
// set (an alternative to myScalarString = "some string")
mutating func set(string: String) {
self.scalarArray.removeAll(keepingCapacity: false)
for s in string.unicodeScalars {
self.scalarArray.append(s.value)
}
}
// split
func split(atChar splitChar: UInt32) -> [ScalarString] {
var partsArray: [ScalarString] = []
var part: ScalarString = ScalarString()
for scalar in self.scalarArray {
if scalar == splitChar {
partsArray.append(part)
part = ScalarString()
} else {
part.append(scalar: scalar) //.append(scalar)
}
}
partsArray.append(part)
return partsArray
}
// startsWith
func startsWith() -> UInt32? {
return self.scalarArray.first
}
// substring
func substring(startIndex: Int) -> ScalarString {
// from startIndex to end of string
var subArray: ScalarString = ScalarString()
for i in startIndex ..< self.length {
subArray.append(scalar: self.scalarArray[i]) //.append(self.scalarArray[i])
}
return subArray
}
func substring(startIndex: Int, _ endIndex: Int) -> ScalarString {
// (startIndex is inclusive, endIndex is exclusive)
var subArray: ScalarString = ScalarString()
for i in startIndex ..< endIndex {
subArray.append(scalar: self.scalarArray[i]) //.append(self.scalarArray[i])
}
return subArray
}
// toString
func toString() -> String {
let string: String = ""
for scalar in self.scalarArray {
string.appending(String(describing:UnicodeScalar(scalar))) //.append(UnicodeScalar(scalar)!)
}
return string
}
// values
func values() -> [UInt32] {
return self.scalarArray
}
}
func ==(left: ScalarString, right: ScalarString) -> Bool {
if left.length != right.length {
return false
}
for i in 0 ..< left.length {
if left.charAt(index: i) != right.charAt(index: i) {
return false
}
}
return true
}
func +(left: ScalarString, right: ScalarString) -> ScalarString {
var returnString = ScalarString()
for scalar in left.values() {
returnString.append(scalar: scalar) //.append(scalar)
}
for scalar in right.values() {
returnString.append(scalar: scalar) //.append(scalar)
}
return returnString
}
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