1.十六进制String(字符串)转Data

1.1 方法一（推荐）：

extension String {
    /// Create `Data` from hexadecimal string representation
    /// This takes a hexadecimal representation and creates a `Data` object. Note, if the string has any spaces or non-hex characters (e.g. starts with '<' and with a '>'), those are ignored and only hex characters are processed.
    /// - returns: Data represented by this hexadecimal string.
    func hexadecimal() -> Data? {
        var data = Data(capacity: self.count / 2)
        let regex = try! NSRegularExpression(pattern: "[0-9a-f]{1,2}", options: .caseInsensitive)
        regex.enumerateMatches(in: self, range: NSMakeRange(0, utf16.count)) { match, flags, stop in
            let byteString = (self as NSString).substring(with: match!.range)
            var num = UInt8(byteString, radix: 16)!
            data.append(&num, count: 1)
        guard data.count > 0 else { return nil }
        return data
1.2 方法二：
 
 //将十六进制字符串转化为 Data
    func data(from hexStr: String) -> Data {
        var hexStr1 = ""
        if hexStr.count % 2 != 0 {
            hexStr1 = "0" + hexStr
        }else {
            hexStr1 = hexStr
        let bytes = self.bytes(from: hexStr1)
        return Data(bytes: bytes)
2.十六进制字符串转bytes[UInt8]
 
 // 将16进制字符串转化为 [UInt8]
    // 使用的时候直接初始化出 Data
    // Data(bytes: Array<UInt8>)
   func bytes(from hexStr: String) -> [UInt8] {
//        print("hexStr:\(hexStr)")
        assert(hexStr.count % 2 == 0, "输入字符串格式不对，8位代表一个字符")
        var bytes = [UInt8]()
        var sum = 0
        // 整形的 utf8 编码范围
        let intRange = 48...57
        // 小写 a~f 的 utf8 的编码范围
        let lowercaseRange = 97...102
        // 大写 A~F 的 utf8 的编码范围
        let uppercasedRange = 65...70
        for (index, c) in hexStr.utf8CString.enumerated() {
            var intC = Int(c.byteSwapped)
            if intC == 0 {
                break
            } else if intRange.contains(intC) {
                intC -= 48
            } else if lowercaseRange.contains(intC) {
                intC -= 87
            } else if uppercasedRange.contains(intC) {
                intC -= 55
            } else {
                assertionFailure("输入字符串格式不对，每个字符都需要在0~9，a~f，A~F内")
            sum = sum * 16 + intC
            // 每两个十六进制字母代表8位，即一个字节
            if index % 2 != 0 {
                bytes.append(UInt8(sum))
                sum = 0
//    print(bytes)
    print(bytes.count)
        return bytes
3.bytes[UInt8]转十六进制字符串Hex
 
3.1 自己的代码和示例
 
       let bytes:[UInt8] = [0xff,0xaa,0xbb]
        print(bytes)
        print(bytes.toHexStr())
  打印结果：
 [255, 170, 187]
 ff-aa-bb




    
 
extension Data {
//MARK: Data转十六进制字符串
    /// Create hexadecimal string representation of `Data` object.
    /// - returns: `String` representation of this `Data` object.
    func hexadecimal() -> String {
        return map { String(format: "%02x", $0) }
            .joined(separator: "-")
extension Array where Element == UInt8 {
//MARK: bytes[UInt8]转十六进制字符串
    /// Create hexadecimal string representation of `Data` object.
    /// - returns: `String` representation of this `Data` object.
    func toHexStr() -> String {
        let data:Data = Data.init(bytes: self)
        return data.hexadecimal()
3.2 bytes[UInt8],Data,NSData转十六进制字符串，mac地址“AA:BB:CC:DD:EE:FF”
 
extension NSData {
    func macStr()->String {
        var bytes:[UInt8] = [UInt8](self as Data)
        bytes.removeFirst()
        bytes.removeFirst()
        var macStr = bytes.toHexStr()
        return macStr.uppercased()
extension Data {
    /// Create hexadecimal string representation of `Data` object.
    /// - returns: `String` representation of this `Data` object.
    func macStr() -> String {
        return map { String(format: "%02x", $0) }
            .joined(separator: ":")
extension Array where Element == UInt8 {
//MARK: bytes[UInt8]转十六进制字符串
    /// Create hexadecimal string representation of `Data` object.
    /// - returns: `String` representation of this `Data` object.
    func toHexStr() -> String {
        let data:Data = Data.init(bytes: self)
        return data.macStr()
3.2 可以用CryptoSwift框架中的数据转换方法
 
数据加密和转换的框架：
 CryptoSwift - github 
4.Data转十六进制String
 
extension Data {
    /// Create hexadecimal string representation of `Data` object.
    /// - returns: `String` representation of this `Data` object.
    func hexadecimal() -> String {
        return map { String(format: "%02x", $0) }
            .joined(separator: "")
5.Data,NSData,bytes[UInt8]互转
 
playground
  
bytes: [UInt8] 
let data:Data = Data.init(bytes: bytes);         
let nsdata:NSData = NSData.init(bytes: bytes, length: bytes.count);
data: Data 
let bytes: [UInt8] = [UInt8](data)  
let nsdata: NSData = NSData(data: data)
nsdata: NSData 
let bytes: [UInt8] = [UInt8](nsdata as Data)
let data: Data = nsdata as Data
参考博客：
 
（iOS, Swift）十六进制转Data，十六进制转整形，Data转String
 swift 16进制String和Data相互转换
 Swift中，把NSData转换为Byte数组的三种方法
  for (let i = 0; i < b.length; i++) {
    let hex = (b[i]).toString(16);
    if (hex.length === 1) {
      hexs = '0' + hex;
    hexs += hex.toUpperCase();
				本文实例讲述了javascript实现的字符串与十六进制表示字符串相互转换方法。分享给大家供大家参考。具体如下：
之所以写这个，是因为发现SQL注入和XSS中经常利用十六进制表示的字符串，比如
SELECT CONCAT(0x68656c6c6f);
得到的是hello
<!DOCTYPE html>
  <title>Hex-Char Bi-Converter</title>
 </head>
  <div class=mainContainer>
   <label for=from id=fromLabel>String</la
- (instancetype)initWithBytesNoCopy:(void *)bytes length:(NSUInteger)length freeWhenDone:(BOOL)b;
初始化对象。
不进行复制字节数组操作，直接设置字节指针为bytes，长度为length。
- (instancetype)i...
    let nowDate = Date()  
    let timeZone = TimeZone.init(identifier: "UTC")  
    let formatter = DateFormatter()  
				1 String 类型转 NSData 类型
       dataUsingEncoding函数： 将字符串类型（String）的数据转换成数据类型(NSData) 的数据。
String类中有自带的函数方法：
public
dataUsingEncoding(encoding:
NSStringEncoding, allowLossyC
日期转成字符串。这个虽然简单，但是我相信很多朋友初次遇到肯定束手无策。脑子里蹦出四个字：这怎么转？直接上代码：
//获取系统当前时间
NSDate *currentDate = [NSDate date];
//用于格式化NSDate对象
NSDateFormatter *dateFormatter = [[NSDat...
+ (NSString *)hexStringFromString:(NSString *)string
    NSData *myD = [string dataUsingEncoding:NSUTF8StringEncoding];
    Byte *bytes = (Byte *)[myD bytes];
    //下面是Byte 转换为16进制。
    NSMutableString* resultStr = [[NSMutableString alloc]in
#pragma mark - 十六进制转换工具
// 16进制转NSData
- (NSData *)convertHexStrToData:(NSString *)str
    if (!str || [str length] == 0) {
        return nil;
    NSMutableData *hexData = [[NSMutableDa...
```cpp
QString hexString = "1A2B3C";
QByteArray hexData = QByteArray::fromHex(hexString.toUtf8());
qDebug() << hexData.toHex();
这里将字符串"1A2B3C"转换为QByteArray类型的hexData，再使用toHex方法输出16进制数值。