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。
斯威夫特5
func isValidEmailAddress(emailAddressString: String) -> Bool {
var returnValue = true
let emailRegEx = "[A-Z0-9a-z.-_]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,3}"
do {
let regex = try NSRegularExpression(pattern: emailRegEx)
let nsString = emailAddressString as NSString
let results = regex.matches(in: emailAddressString, range: NSRange(location: 0, length: nsString.length))
if results.count == 0
{
returnValue = false
}
} catch let error as NSError {
print("invalid regex: \(error.localizedDescription)")
returnValue = false
}
return returnValue
}
然后:
let validEmail = isValidEmailAddress(emailAddressString: "your@email.com")
print(validEmail)
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
}
}
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 ...
}
}
}
这是@Fattie的“THE REASONABLE SOLUTION”的新版本，在Swift 4.1的一个名为String+Email.swift的新文件中测试:
import Foundation
extension String {
private static let __firstpart = "[A-Z0-9a-z]([A-Z0-9a-z._%+-]{0,30}[A-Z0-9a-z])?"
private static let __serverpart = "([A-Z0-9a-z]([A-Z0-9a-z-]{0,30}[A-Z0-9a-z])?\\.){1,5}"
private static let __emailRegex = __firstpart + "@" + __serverpart + "[A-Za-z]{2,6}"
public var isEmail: Bool {
let predicate = NSPredicate(format: "SELF MATCHES %@", type(of:self).__emailRegex)
return predicate.evaluate(with: self)
}
}
所以它的用法很简单:
let str = "mail@domain.com"
if str.isEmail {
print("\(str) is a valid e-mail address")
} else {
print("\(str) is not a valid e-mail address")
}
我只是不喜欢向String对象添加func，因为作为电子邮件地址是它们固有的(或不是)。根据我的理解，Bool属性比func更适合。
