电子邮件验证 swift 2答案

【问题标题】：Email validation swift 2电子邮件验证 swift 2
【发布时间】：2016-10-23 15:29:00
【问题描述】：

如何限制用户在文本字段中输入电子邮件地址。问题是，我的警报没有显示，只需注册而不检查电子邮件字段是否有效

if ( username.isEmpty || email.isEmpty || password.isEmpty || phonenumper.isEmpty) {

    let alert = UIAlertController(title: "Sign Up Failed!", message:"Please enter your data for Signup", preferredStyle: .Alert)
    alert.addAction(UIAlertAction(title: "OK ", style: .Default) { _ in })
    self.presentViewController(alert, animated: true){}
}

else {
    if (isValidEmail(UserEmailTextFiled.text!)) {
        let alert = UIAlertController(title: "Inviled Email", message:"Please enter your Email", preferredStyle: .Alert)
        alert.addAction(UIAlertAction(title: "OK ", style: .Default) { _ in })
        self.presentViewController(alert, animated: true){}

    }else{
    //code

    }
func isValidEmail(testStr:String) -> Bool {
        let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
        let range = testStr.rangeOfString(emailRegEx, options:.RegularExpressionSearch)
        let result = range != nil ? true : false
        return result
    }

【问题讨论】：

我建议您更新 isValidEmail 以将可选字符串作为参数，而不是字符串，如果它为 nil，则返回 false。它可以避免崩溃（你总是在不检查的情况下打开可选值）
旁注，因为这实际上不是您问题的一部分，但我建议删除正则表达式。电子邮件地址正则表达式验证过于复杂，您可能无法考虑所有可能性。如果用户输入了无效的电子邮件，那是他们的问题，而不是你的问题。有关更深入的讨论，请参阅此博客文章：davidcel.is/posts/stop-validating-email-addresses-with-regex

标签： ios swift email-validation

【解决方案1】：

swift 3.0 中的电子邮件验证

@IBOutlet weak var emailid: UILabel!
@IBOutlet weak var MsgAlrtEmailId: UILabel!

@IBAction func Register(_ sender: Any)
    {
        //email

        let providedEmailAddress = emailid.text

        let isEmailAddressValid = isValidEmailAddress(emailAddressString: providedEmailAddress!)

        if isEmailAddressValid
        {
            print("Email address is valid")
            MsgAlrtEmailId.text = "Email Address is valid"
            MsgAlrtEmailId.sizeToFit()
            MsgAlrtEmailId.textColor = UIColor.blue

        } else {
            print("Email address is not valid")
            MsgAlrtEmailId.text = "Email Address Not valid"
            MsgAlrtEmailId.sizeToFit()
           MsgAlrtEmailId.textColor = UIColor.red
        }

  //email rule validation
        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
        }

【讨论】：

【解决方案2】：

public func isValidEmailAddress() -> Bool {
    let emailRegex = "^[\\w!#$%&'*+/=?`{|}~^-]+(?:\\.[\\w!#$%&'*+/=?`{|}~^-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$"
    return NSPredicate(format: "SELF MATCHES %@", emailRegex).evaluate(with: self)
}

这是带有正则表达式的 Swift 3.0 Func。只需复制/粘贴到您的帮助程序或扩展文件中，然后使用它。

【讨论】：

【解决方案3】：

在 Swift 3.0 中

extension  String {

    func nsstring () -> NSString {
        return (self as NSString)
    }

    func isValidEmailAddress () -> 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 results = regex.matches(in: self.trimmingCharacters(in: .whitespacesAndNewlines), range: NSRange(location: 0, length: self.characters.count))
            if results.count == 0
            {
                returnValue = false
            }
        }
        catch let error as NSError
        {
            print("invalid regex: \(error.localizedDescription)")
            returnValue = false
        }
        return  returnValue
    }    
}

在 ViewController 中

let isValidEmail = yourtextField?.text?.isValidEmailAddress()
if isValidEmail!
{ 
 //Code Here
}
else
{
 //Error Code Here
}

【讨论】：

【解决方案4】：

根据您发布的代码，if (isValidEmail(UserEmailTextFiled.text!)) {... 表示如果电子邮件有效，将显示无效电子邮件警报。你只需要用! if (!isValidEmail(UserEmailTextFiled.text!)) { 反转结果

【讨论】：