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。
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
}
}
我建议使用它作为String的扩展:
extension String {
public var isEmail: Bool {
let dataDetector = try? NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
let firstMatch = dataDetector?.firstMatch(in: self, options: NSRegularExpression.MatchingOptions.reportCompletion, range: NSRange(location: 0, length: length))
return (firstMatch?.range.location != NSNotFound && firstMatch?.url?.scheme == "mailto")
}
public var length: Int {
return self.characters.count
}
}
要使用它:
if "hodor@gameofthrones.com".isEmail { // true
print("Hold the Door")
}
如果你正在寻找一个干净简单的解决方案，你应该看看https://github.com/nsagora/validation-components。
它包含一个电子邮件验证谓词，很容易集成在你的代码:
let email = "test@example.com"
let rule = EmailValidationPredicate()
let isValidEmail = rule.evaluate(with: email)
在引擎盖后面，它使用RFC 5322 regex (http://emailregex.com):
let regex = "(?:[\\p{L}0-9!#$%\\&'*+/=?\\^_`{|}~-]+(?:\\.[\\p{L}0-9!#$%\\&'*+/=?\\^_`{|}" +
"~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\" +
"x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[\\p{L}0-9](?:[a-" +
"z0-9-]*[\\p{L}0-9])?\\.)+[\\p{L}0-9](?:[\\p{L}0-9-]*[\\p{L}0-9])?|\\[(?:(?:25[0-5" +
"]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-" +
"9][0-9]?|[\\p{L}0-9-]*[\\p{L}0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21" +
"-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])"
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
}
}
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。
