有人知道如何在Swift中验证电子邮件地址吗?我找到了这个代码:

- (BOOL) validEmail:(NSString*) emailString {

    if([emailString length]==0){
        return NO;
    }

    NSString *regExPattern = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";

    NSRegularExpression *regEx = [[NSRegularExpression alloc] initWithPattern:regExPattern options:NSRegularExpressionCaseInsensitive error:nil];
    NSUInteger regExMatches = [regEx numberOfMatchesInString:emailString options:0 range:NSMakeRange(0, [emailString length])];

    NSLog(@"%i", regExMatches);
    if (regExMatches == 0) {
        return NO;
    } else {
        return YES;
    }
}

但我无法翻译成斯威夫特。


当前回答

在Swift 4.2和Xcode 10.1中

//Email validation
func isValidEmail(email: String) -> Bool {
    let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"
    var valid = NSPredicate(format: "SELF MATCHES %@", emailRegex).evaluate(with: email)
    if valid {
        valid = !email.contains("Invalid email id")
    }
    return valid
}

//Use like this....
let emailTrimmedString = emailTF.text?.trimmingCharacters(in: .whitespaces)
if isValidEmail(email: emailTrimmedString!) == false {
   SharedClass.sharedInstance.alert(view: self, title: "", message: "Please enter valid email")
}

如果你想使用SharedClass。

//This is SharedClass
import UIKit
class SharedClass: NSObject {

static let sharedInstance = SharedClass()

//Email validation
func isValidEmail(email: String) -> Bool {
    let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"
    var valid = NSPredicate(format: "SELF MATCHES %@", emailRegex).evaluate(with: email)
    if valid {
        valid = !email.contains("Invalid email id")
    }
    return valid
}

private override init() {

}
}

并调用这样的函数....

if SharedClass.sharedInstance. isValidEmail(email: emailTrimmedString!) == false {
   SharedClass.sharedInstance.alert(view: self, title: "", message: "Please enter correct email")
   //Your code here
} else {
   //Code here
}

其他回答

我更喜欢用扩展名。此外,这个url http://emailregex.com可以帮助您测试regex是否正确。事实上,该站点为某些编程语言提供了不同的实现。我分享了Swift 3的实现。

extension String {
    func validateEmail() -> Bool {
        let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,6}"
        return NSPredicate(format: "SELF MATCHES %@", emailRegex).evaluate(with: self)
    }
}

在Swift 5.7中,在Regex类的帮助下,我们可以以简单有效的方式验证电子邮件地址

private func isValidEmail(_ email: String) -> Bool {
      guard let emailRegex = try? Regex("[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}")  
      else { return false }
      return email.firstMatch(of: emailRegex) != nil
   }

我们还可以使用属性包装器来提高效率:

@propertyWrapper
struct EmailPropertyWrapper {
  private var _value: String
  var wrappedValue: String {
    get { return isValidEmail(_value) ? _value : String() }
    set { _value = newValue }
  }
  
  init(email: String) {
    _value = email
  }

  private func isValidEmail(_ email: String) -> Bool {
      guard let emailRegex = try? Regex("[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}")  
      else { return false }
      return email.firstMatch(of: emailRegex) != nil
   }
}

struct User {
  var name: String
  @EmailPropertyWrapper var email: String
  
  func validateProperty() -> Bool {
    if name.isEmpty || email.isEmpty { return false }
    return true
  }
}

let user = User(name: "Sy", email: .init(email: "wwdc@icloud.com"))

print(user.validateProperty())

更新答案@Arsonik对Swift 2.2的回答,使用比其他提供的解决方案更少的冗长代码:

extension String {
    func isValidEmail() -> Bool {
        let regex = try? NSRegularExpression(pattern: "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$", options: .CaseInsensitive)
        return regex?.firstMatchInString(self, options: [], range: NSMakeRange(0, self.characters.count)) != nil
    }
}

作为String类扩展

斯威夫特4

extension String {
    func isValidEmail() -> Bool {
        // here, `try!` will always succeed because the pattern is valid
        let regex = try! NSRegularExpression(pattern: "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$", options: .caseInsensitive)
        return regex.firstMatch(in: self, options: [], range: NSRange(location: 0, length: count)) != nil
    }
}

使用

if "rdfsdsfsdfsd".isValidEmail() {

}

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。