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

我改进了@Azik的答案。我允许使用准则允许的更多特殊字符,并返回一些无效的额外边缘情况。

小组认为这里只允许本地部分的。_%+-是不正确的。参见@Anton Gogolev对这个问题的回答或参见下文:

The local-part of the email address may use any of these ASCII characters: uppercase and lowercase Latin letters A to Z and a to z; digits 0 to 9; special characters !#$%&'*+-/=?^_`{|}~; dot ., provided that it is not the first or last character unless quoted, and provided also that it does not appear consecutively unless quoted (e.g. John..Doe@example.com is not allowed but "John..Doe"@example.com is allowed); space and "(),:;<>@[\] characters are allowed with restrictions (they are only allowed inside a quoted string, as described in the paragraph below, and in addition, a backslash or double-quote must be preceded by a backslash); comments are allowed with parentheses at either end of the local-part; e.g. john.smith(comment)@example.com and (comment)john.smith@example.com are both equivalent to john.smith@example.com;

我使用的代码将不允许限制性的特殊字符,但将允许比这里的大多数答案更多的选项。我更喜欢更宽松的验证,而不是谨慎的错误。

if enteredText.contains("..") || enteredText.contains("@@") 
   || enteredText.hasPrefix(".") || enteredText.hasSuffix(".con"){
       return false
}

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: enteredText)

其他回答

编辑,针对Swift 3更新:

func validateEmail(enteredEmail: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: enteredEmail)

}

Swift 2的原始答案:

func validateEmail(enteredEmail: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.evaluateWithObject(enteredEmail)

}

它工作得很好。

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
}

我唯一添加到响应列表的是,对于Linux, NSRegularExpression不存在,它实际上是RegularExpression

    func isEmail() -> Bool {

    let patternNormal = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,6}"

    #if os(Linux)
        let regex = try? RegularExpression(pattern: patternNormal, options: .caseInsensitive)
    #else
        let regex = try? NSRegularExpression(pattern: patternNormal, options: .caseInsensitive)
    #endif

    return regex?.firstMatch(in: self, options: [], range: NSMakeRange(0, self.characters.count)) != nil

在macOS和Ubuntu上都能成功编译。

Swift 4.2的使用

extension String {
    func isValidEmail() -> Bool {
        let regex = try? NSRegularExpression(pattern: "^(((([a-zA-Z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])+(\\.([a-zA-Z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])+)*)|((\\x22)((((\\x20|\\x09)*(\\x0d\\x0a))?(\\x20|\\x09)+)?(([\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f]|\\x21|[\\x23-\\x5b]|[\\x5d-\\x7e]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(\\([\\x01-\\x09\\x0b\\x0c\\x0d-\\x7f]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}]))))*(((\\x20|\\x09)*(\\x0d\\x0a))?(\\x20|\\x09)+)?(\\x22)))@((([a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(([a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])([a-zA-Z]|\\d|-|\\.|_|~|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*([a-zA-Z]|\\d|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.)+(([a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])|(([a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])([a-zA-Z]|\\d|-|_|~|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*([a-zA-Z]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.?$", options: .caseInsensitive)
        return regex?.firstMatch(in: self, options: [], range: NSMakeRange(0, self.count)) != nil
    }
    func isValidName() -> Bool{
        let regex = try? NSRegularExpression(pattern: "^[\\p{L}\\.]{2,30}(?: [\\p{L}\\.]{2,30}){0,2}$", options: .caseInsensitive)

        return regex?.firstMatch(in: self, options: [], range: NSMakeRange(0, self.count)) != nil
    } }

和使用

if (textField.text?.isValidEmail())! 
    {
      // bla bla
    }
else 
    {

    }

我改进了@Azik的答案。我允许使用准则允许的更多特殊字符,并返回一些无效的额外边缘情况。

小组认为这里只允许本地部分的。_%+-是不正确的。参见@Anton Gogolev对这个问题的回答或参见下文:

The local-part of the email address may use any of these ASCII characters: uppercase and lowercase Latin letters A to Z and a to z; digits 0 to 9; special characters !#$%&'*+-/=?^_`{|}~; dot ., provided that it is not the first or last character unless quoted, and provided also that it does not appear consecutively unless quoted (e.g. John..Doe@example.com is not allowed but "John..Doe"@example.com is allowed); space and "(),:;<>@[\] characters are allowed with restrictions (they are only allowed inside a quoted string, as described in the paragraph below, and in addition, a backslash or double-quote must be preceded by a backslash); comments are allowed with parentheses at either end of the local-part; e.g. john.smith(comment)@example.com and (comment)john.smith@example.com are both equivalent to john.smith@example.com;

我使用的代码将不允许限制性的特殊字符,但将允许比这里的大多数答案更多的选项。我更喜欢更宽松的验证,而不是谨慎的错误。

if enteredText.contains("..") || enteredText.contains("@@") 
   || enteredText.hasPrefix(".") || enteredText.hasSuffix(".con"){
       return false
}

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: enteredText)