这是一个最新的游乐场兼容版本，使用标准库，所以你不需要维护一个正则表达式:

import Foundation

func isValid(email: String) -> Bool {
  do {
    let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
    let range = NSRange(location: 0, length: email.count)
    let matches = detector.matches(in: email, options: .anchored, range: range)
    guard matches.count == 1 else { return false }
    return matches[0].url?.scheme == "mailto"
  } catch {
    return false
  }
}

extension String {
  var isValidEmail: Bool {
    isValid(email: self)
  }
}

let email = "test@mail.com"
isValid(email: email) // prints 'true'
email.isValidEmail // prints 'true'

//Email validation
func validateEmail(enterEmail:String) -> Bool{
    let emailFormat = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
    let emailPredicate = NSPredicate(format:"SELF MATCHES %@",emailFormat)
    return emailPredicate.evaluate(with:enterEmail)
}

100%工作和测试

@JeffersonBe的答案是接近的，但如果字符串是“包含someone@something.com一个有效的电子邮件”，这不是我们想要的。下面是String上的一个扩展，它工作得很好(并且允许测试有效的phoneNumber和其他数据检测器来引导。

/// Helper for various data detector matches.
/// Returns `true` iff the `String` matches the data detector type for the complete string.
func matchesDataDetector(type: NSTextCheckingResult.CheckingType, scheme: String? = nil) -> Bool {
    let dataDetector = try? NSDataDetector(types: type.rawValue)
    guard let firstMatch = dataDetector?.firstMatch(in: self, options: NSRegularExpression.MatchingOptions.reportCompletion, range: NSRange(location: 0, length: length)) else {
        return false
    }
    return firstMatch.range.location != NSNotFound
        // make sure the entire string is an email, not just contains an email
        && firstMatch.range.location == 0
        && firstMatch.range.length == length
        // make sure the link type matches if link scheme
        && (type != .link || scheme == nil || firstMatch.url?.scheme == scheme)
}
/// `true` iff the `String` is an email address in the proper form.
var isEmail: Bool {
    return matchesDataDetector(type: .link, scheme: "mailto")
}
/// `true` iff the `String` is a phone number in the proper form.
var isPhoneNumber: Bool {
    return matchesDataDetector(type: .phoneNumber)
}
/// number of characters in the `String` (required for above).
var length: Int {
    return self.characters.count
}

以下是目前Swiftmailer中一个非常简单的方法。其他大多数答案都是老掉牙的。

根据Swiftmailer文档: https://swiftmailer.symfony.com/docs/messages.html#quick-reference

use Egulias\EmailValidator\EmailValidator;
use Egulias\EmailValidator\Validation\RFCValidation;

$validator = new EmailValidator();
$validator->isValid("example@example.com", new RFCValidation()); //true

在我看来，这是迄今为止最简单、最健壮的方法。只需通过Composer安装egalias \EmailValidator库，它应该已经作为SwiftMailer的依赖项引入了。

似乎也有用……

let regex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"

func validate(email: String) -> Bool {
    let matches = email.rangeOfString(regex, options: .RegularExpressionSearch)
    if let _ = matches {
        return true
    }
    return false
}

或者你可以扩展可选文本UITextField:

使用方法:

if  emailTextField.text.isEmailValid() {
      print("email is valid")
}else{
      print("wrong email address")
}

扩展:

extension Optional where Wrapped == String {
    func isEmailValid() -> Bool{
        guard let email = self else { return false }
        let emailPattern = "[A-Za-z-0-9.-_]+@[A-Za-z0-9]+\\.[A-Za-z]{2,3}"
        do{
            let regex = try NSRegularExpression(pattern: emailPattern, options: .caseInsensitive)
            let foundPatters = regex.numberOfMatches(in: email, options: .anchored, range: NSRange(location: 0, length: email.count))
            if foundPatters > 0 {
                return true
            }
        }catch{
            //error
        }
        return false
    }
}