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

我为输入验证设计了一个库,其中一个“模块”可以让你轻松地验证一堆东西…

例如,要验证一封电子邮件:

let emailTrial = Trial.Email
let trial = emailTrial.trial()

if(trial(evidence: "test@test.com")) {
   //email is valid
}

SwiftCop是图书馆…希望能有所帮助!

其他回答

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
}

我会使用npredicate:

func isValidEmail(_ email: String) -> Bool {        
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

    let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
    return emailPred.evaluate(with: email)
}

对于Swift 3.0之前的版本:

func isValidEmail(email: String) -> Bool {
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

    let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
    return emailPred.evaluate(with: email)
}

对于Swift 1.2之前的版本:

func isValidEmail(email: String) -> Bool {
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

    if let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx) {
        return emailPred.evaluateWithObject(email)
    }
    return false
}

Swift 5 -可伸缩的验证层

使用此层,您将轻松地在任何文本字段上获得惊人的验证。

只需遵循以下流程即可。

1. 添加这些枚举:

import Foundation

enum ValidatorType
{
    case email
    case name
    // add more cases ...
}

enum ValidationError: Error, LocalizedError
{
    case invalidUserName
    case invalidEmail
    // add more cases ...

    var localizedDescription: String
    {
        switch self
        {
        case .invalidEmail:
            return "Please kindly write a valid email"    
        case .invalidUserName:
            return "Please kindly write a valid user name"
        }
    }
}

2. 将此功能添加到String:

extension String
{
    // MARK:- Properties

    var isValidEmail: 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: self)
    }

    // MARK:- Methods

    func validatedText(_ validationType: ValidatorType) throws
    {
        switch validationType
        {
            case .name:
                try validateUsername()
            case .email:
                try validateEmail()
        }
    }

    // MARK:- Private Methods

    private func validateUsername() throws
    {
        if isEmpty
        {
            throw ValidationError.invalidUserName
        }
    }

    private func validateEmail() throws
    {
        if !isValidEmail 
        {
            throw ValidationError.invalidEmail
        }

        // add more validations if you want like empty email
    }
}

3.添加以下功能到UITextField:

import UIKit

extension UITextField
{
    func validatedText(_ validationType: ValidatorType) throws
    {
        do
        {
            try text?.validatedText(validationType)
        }
        catch let validationError
        {
            shake()
            throw validationError
        }
    }

    // MARK:- Private Methods

    private func shake()
    {
        let animation = CABasicAnimation(keyPath: "position")
        animation.duration = 0.1
        animation.repeatCount = 5
        animation.fromValue = NSValue(cgPoint: CGPoint(x: center.x + 6, y: center.y))
        animation.toValue = NSValue(cgPoint: CGPoint(x: center.x - 6, y: center.y))
        layer.add(animation, forKey: "position")
    }
}

使用

import UIKit

class LoginVC: UIViewController
{
    // MARK: Outlets

    @IBOutlet weak var textFieldEmail: UITextField!

    // MARK: View Controller Life Cycle

    override func viewDidLoad()
    {
        super.viewDidLoad()
    }

    // MARK: Methods

    private func checkEmail() -> Bool
    {
        do
        {
            try textFieldEmail.validatedText(.email)
        }
        catch let error
        {
            let validationError = error as! ValidationError
            // show alert to user with: validationError.localizedDescription
            return false
        }

        return true
    }

    // MARK: Actions

    @IBAction func loginTapped(_ sender: UIButton)
    {
        if checkEmail()
        {
            let email = textFieldEmail.text!
            // move safely ...
        }
    }
}

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
    }
}

完美的正则表达式,如谷歌电子邮件

"^[A-Z0-9a-z][a-zA-Z0-9_.-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"