blocks|key|79231|text|这是Swift+2.0+-+2.2的更新版本|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79232|+var+isEmail:+Bool+{
++++do+{
++++++++let+regex+=+try+NSRegularExpression(pattern:+"%5E[a-zA-Z0-9.!#$%25&'*%2B/=?%5E_`{%7C}~-]%2B@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$",+options:+.CaseInsensitive)
++++++++return+regex.firstMatchInString(self,+options:+NSMatchingOptions(rawValue:+0),+range:+NSMakeRange(0,+self.characters.count))+!=+nil
++++}+catch+{
++++++++return+false
++++}
}|code-block|syntax|javascript|79233|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is the updated version for Swift 2.0 - 2.2

<pre><code> var isEmail: Bool {
 do {
 let regex = try NSRegularExpression(pattern: "^[a-zA-Z0-9.!#$%&amp;'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$", options: .CaseInsensitive)
 return regex.firstMatchInString(self, options: NSMatchingOptions(rawValue: 0), range: NSMakeRange(0, self.characters.count)) != nil
 } catch {
 return false
 }
}
</code></pre>

blocks|key|79257|text|下面是投票最多的两个答案与正确的正则表达式的融合:使用predicate的字符串扩展，因此可以调用string.isEmail|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79258|++++extension+String+{
++++++++var+isEmail:+Bool+{
+++++++++++let+emailRegEx+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,20}"++++++++++++
+++++++++++let+emailTest++=+NSPredicate(format:"SELF+MATCHES+%25@",+emailRegEx)
+++++++++++return+emailTest.evaluateWithObject(self)
++++++++}
++++}|code-block|syntax|javascript|79259|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here is a fuse of the two most up-voted answer with the correct regex: a String extension using predicate so you can call string.isEmail

<pre><code> extension String {
 var isEmail: Bool {
 let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,20}" 
 let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
 return emailTest.evaluateWithObject(self)
 }
 }
</code></pre>

blocks|key|79284|text|我做了一个为输入验证而设计的库，其中一个“模块”允许你轻松地验证一堆东西……|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79285|例如，要验证电子邮件：|79286|let+emailTrial+=+Trial.Email
let+trial+=+emailTrial.trial()

if(trial(evidence:+"test@test.com"))+{
+++//email+is+valid
}|code-block|syntax|javascript|79287|SwiftCop是库..。希望它能帮上忙！|offset|length|79288|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/andresinaka/SwiftCop^0|0|0|0|0|8|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@$K|Y|L|Z|1|10]]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

I made a library designed for input validations and one of the "modules" allows you to easily validate a bunch of stuff... 

For example to validate an email:

<pre><code>let emailTrial = Trial.Email
let trial = emailTrial.trial()

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

<a href="https://github.com/andresinaka/SwiftCop" rel="nofollow">SwiftCop</a> is the library... hope it help!

blocks|key|79302|text|对于swift+2.1:通过电子邮件foo@bar可以正常工作|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79303|extension+String+{
++++func+isValidEmail()+->+Bool+{
++++++++do+{
++++++++++++let+regex+=+try+NSRegularExpression(pattern:+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,6}",+options:+.CaseInsensitive)
++++++++++++return+regex.firstMatchInString(self,+options:+NSMatchingOptions(rawValue:+0),+range:+NSMakeRange(0,+self.characters.count))+!=+nil
++++++++}+catch+{
++++++++++++++++return+false
++++++++}
++++}
}|code-block|syntax|javascript|79304|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

For swift 2.1: this works correctly with email foo@bar

<pre><code>extension String {
 func isValidEmail() -&gt; Bool {
 do {
 let regex = try NSRegularExpression(pattern: "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,6}", options: .CaseInsensitive)
 return regex.firstMatchInString(self, options: NSMatchingOptions(rawValue: 0), range: NSMakeRange(0, self.characters.count)) != nil
 } catch {
 return false
 }
 }
}
</code></pre>

blocks|key|79332|text|由于现在有这么多奇怪的顶级域名，我不再检查顶级域名的长度…|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79333|下面是我使用的代码：|79334|extension+String+{

++++func+isEmail()+->+Bool+{
++++++++let+emailRegEx+=+"%5E[a-zA-Z0-9_.%2B-]%2B@[a-zA-Z0-9-]%2B\\.[a-zA-Z0-9-.]%2B$"
++++++++return+NSPredicate(format:"SELF+MATCHES+%25@",+emailRegEx).evaluateWithObject(self)
++++}+
}|code-block|syntax|javascript|79335|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Since there are so many weird top level domain name now, I stop checking the length of the top domain...

Here is what I use:

<pre><code>extension String {

 func isEmail() -&gt; Bool {
 let emailRegEx = "^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\\.[a-zA-Z0-9-.]+$"
 return NSPredicate(format:"SELF MATCHES %@", emailRegEx).evaluateWithObject(self)
 } 
}
</code></pre>

blocks|key|79383|text|这里有很多正确的答案，但许多“正则表达式”是不完整的，可能会发生这样的情况："name@domain“这样的电子邮件会导致一个有效的电子邮件，但它不是。下面是完整的解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79384|extension+String+{

++++var+isEmailValid:+Bool+{
++++++++do+{
++++++++++++let+regex+=+try+NSRegularExpression(pattern:+"(?:[a-z0-9!#$%25\\&'*%2B/=?\\%5E_`{%7C}~-]%2B(?:\\.[a-z0-9!#$%25\\&'*%2B/=?\\%5E_`{%7C}~-]%2B)*%7C\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\x7f]%7C\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)%2B[a-z0-9](?:[a-z0-9-]*[a-z0-9])?%7C\\[(?:(?:25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?%7C[a-z0-9-]*[a-z0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21-\\x5a\\x53-\\x7f]%7C\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])%2B)\\])",+options:+.CaseInsensitive)
++++++++++++return+regex.firstMatchInString(self,+options:+NSMatchingOptions(rawValue:+0),+range:+NSMakeRange(0,+self.characters.count))+!=+nil
++++++++}+catch+{
++++++++++++return+false
++++++++}
++++}
}|code-block|syntax|javascript|79385|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

There are a lot of right answers here, but many of the "regex" are incomplete and it can happen that an email like: "name@domain" results a valid email, but it is not. Here the complete solution:

<pre><code>extension String {

 var isEmailValid: Bool {
 do {
 let regex = try NSRegularExpression(pattern: "(?:[a-z0-9!#$%\\&amp;'*+/=?\\^_`{|}~-]+(?:\\.[a-z0-9!#$%\\&amp;'*+/=?\\^_`{|}~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\\[(?:(?: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]?|[a-z0-9-]*[a-z0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])", options: .CaseInsensitive)
 return regex.firstMatchInString(self, options: NSMatchingOptions(rawValue: 0), range: NSMakeRange(0, self.characters.count)) != nil
 } catch {
 return false
 }
 }
}
</code></pre>

blocks|key|79405|text|编辑，针对Swift+3更新：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79406|func+validateEmail(enteredEmail:String)+->+Bool+{

++++let+emailFormat+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,64}"
++++let+emailPredicate+=+NSPredicate(format:"SELF+MATCHES+%25@",+emailFormat)
++++return+emailPredicate.evaluate(with:+enteredEmail)

}|code-block|syntax|javascript|79407|Swift+2的原始答案：|79408|func+validateEmail(enteredEmail:String)+->+Bool+{

++++let+emailFormat+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,64}"
++++let+emailPredicate+=+NSPredicate(format:"SELF+MATCHES+%25@",+emailFormat)
++++return+emailPredicate.evaluateWithObject(enteredEmail)

}|79409|它运行良好。|79410|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Editing, updated for Swift 3:

<pre><code>func validateEmail(enteredEmail:String) -&gt; 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)

}
</code></pre>

Original answer for Swift 2:

<pre><code>func validateEmail(enteredEmail:String) -&gt; 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)

}
</code></pre>

It's working fine.

blocks|key|79446|text|似乎也行得通...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79447|let+regex+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,}"

func+validate(email:+String)+->+Bool+{
++++let+matches+=+email.rangeOfString(regex,+options:+.RegularExpressionSearch)
++++if+let+_+=+matches+{
++++++++return+true
++++}
++++return+false
}|code-block|syntax|javascript|79448|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Seems to work too...

<pre><code>let regex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"

func validate(email: String) -&gt; Bool {
 let matches = email.rangeOfString(regex, options: .RegularExpressionSearch)
 if let _ = matches {
 return true
 }
 return false
}
</code></pre>

blocks|key|4586161|text|我建议将其用作String的扩展：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4586162|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
++++}
}|code-block|syntax|javascript|4586163|并使用它：|4586164|if+"hodor@gameofthrones.com".isEmail+{+//+true
++++print("Hold+the+Door")
}|4586165|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I would suggest using it as an extension of String: 

<pre><code>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 &amp;&amp; firstMatch?.url?.scheme == "mailto")
 }

 public var length: Int {
 return self.characters.count
 }
}
</code></pre>

And to use it:

<pre><code>if "hodor@gameofthrones.com".isEmail { // true
 print("Hold the Door")
}
</code></pre>

blocks|key|79524|text|更新了answer+@Arsonik对Swift+2.2的回答，与其他提供的解决方案相比，使用的代码更少：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79525|extension+String+{
++++func+isValidEmail()+->+Bool+{
++++++++let+regex+=+try?+NSRegularExpression(pattern:+"%5E[a-zA-Z0-9.!#$%25&'*%2B/=?%5E_`{%7C}~-]%2B@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$",+options:+.CaseInsensitive)
++++++++return+regex?.firstMatchInString(self,+options:+[],+range:+NSMakeRange(0,+self.characters.count))+!=+nil
++++}
}|code-block|syntax|javascript|79526|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Updated answer @Arsonik answer to Swift 2.2, using less verbose code than other offered solutions:

<pre><code>extension String {
 func isValidEmail() -&gt; Bool {
 let regex = try? NSRegularExpression(pattern: "^[a-zA-Z0-9.!#$%&amp;'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$", options: .CaseInsensitive)
 return regex?.firstMatchInString(self, options: [], range: NSMakeRange(0, self.characters.count)) != nil
 }
}
</code></pre>

blocks|key|4586258|text|@JeffersonBe的答案是close，但如果字符串是"something+containing+someone@something.com+a+valid+email“，则返回true，而这不是我们想要的。以下是字符串上的一个扩展，它工作良好(并允许测试有效的phoneNumber和其他数据检测器以启动。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4586259|///+Helper+for+various+data+detector+matches.
///+Returns+`true`+iff+the+`String`+matches+the+data+detector+type+for+the+complete+string.
func+matchesDataDetector(type:+NSTextCheckingResult.CheckingType,+scheme:+String?+=+nil)+->+Bool+{
++++let+dataDetector+=+try?+NSDataDetector(types:+type.rawValue)
++++guard+let+firstMatch+=+dataDetector?.firstMatch(in:+self,+options:+NSRegularExpression.MatchingOptions.reportCompletion,+range:+NSRange(location:+0,+length:+length))+else+{
++++++++return+false
++++}
++++return+firstMatch.range.location+!=+NSNotFound
++++++++//+make+sure+the+entire+string+is+an+email,+not+just+contains+an+email
++++++++&&+firstMatch.range.location+==+0
++++++++&&+firstMatch.range.length+==+length
++++++++//+make+sure+the+link+type+matches+if+link+scheme
++++++++&&+(type+!=+.link+%7C%7C+scheme+==+nil+%7C%7C+firstMatch.url?.scheme+==+scheme)
}
///+`true`+iff+the+`String`+is+an+email+address+in+the+proper+form.
var+isEmail:+Bool+{
++++return+matchesDataDetector(type:+.link,+scheme:+"mailto")
}
///+`true`+iff+the+`String`+is+a+phone+number+in+the+proper+form.
var+isPhoneNumber:+Bool+{
++++return+matchesDataDetector(type:+.phoneNumber)
}
///+number+of+characters+in+the+`String`+(required+for+above).
var+length:+Int+{
++++return+self.characters.count
}|code-block|syntax|javascript|4586260|entityMap^0|2J|4|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

@JeffersonBe's answer is close, but returns <code>true</code> if the string is "something containing someone@something.com a valid email" which is not what we want. The following is an extension on String that works well (and allows testing for valid phoneNumber and other data detectors to boot.

<pre><code>/// Helper for various data detector matches.
/// Returns `true` iff the `String` matches the data detector type for the complete string.
func matchesDataDetector(type: NSTextCheckingResult.CheckingType, scheme: String? = nil) -&gt; Bool {
 let dataDetector = try? NSDataDetector(types: type.rawValue)
 guard let firstMatch = dataDetector?.firstMatch(in: self, options: NSRegularExpression.MatchingOptions.reportCompletion, range: NSRange(location: 0, length: length)) else {
 return false
 }
 return firstMatch.range.location != NSNotFound
 // make sure the entire string is an email, not just contains an email
 &amp;&amp; firstMatch.range.location == 0
 &amp;&amp; firstMatch.range.length == length
 // make sure the link type matches if link scheme
 &amp;&amp; (type != .link || scheme == nil || firstMatch.url?.scheme == scheme)
}
/// `true` iff the `String` is an email address in the proper form.
var isEmail: Bool {
 return matchesDataDetector(type: .link, scheme: "mailto")
}
/// `true` iff the `String` is a phone number in the proper form.
var isPhoneNumber: Bool {
 return matchesDataDetector(type: .phoneNumber)
}
/// number of characters in the `String` (required for above).
var length: Int {
 return self.characters.count
}
</code></pre>

blocks|key|79656|text|我在回答列表中唯一的补充是，对于Linux，NSRegularExpression不存在，它实际上是RegularExpression。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|79657|++++func+isEmail()+->+Bool+{

++++let+patternNormal+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[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|code-block|syntax|javascript|79658|它在macOS和Ubuntu上都能成功编译。|79659|entityMap^0|M|J|1E|H|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

My only addition to the list of responses would be that for Linux, <code>NSRegularExpression</code> does not exist, it's actually <code>RegularExpression</code>

<pre><code> func isEmail() -&gt; 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
</code></pre>

This compiles successfully on both macOS &amp; Ubuntu.

blocks|key|79712|text|创建简单扩展：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79713|extension+NSRegularExpression+{

++++convenience+init(pattern:+String)+{
++++++++try!+self.init(pattern:+pattern,+options:+[])
++++}
}

extension+String+{

++++var+isValidEmail:+Bool+{
++++++++return+isMatching(expression:+NSRegularExpression(pattern:+"%5E[A-Z0-9a-z\\._%25%2B-]%2B@([A-Za-z0-9-]%2B\\.)%2B[A-Za-z]{2,4}$"))
++++}

++++//MARK:+-+Private

++++private+func+isMatching(expression:+NSRegularExpression)+->+Bool+{
++++++++return+expression.numberOfMatches(in:+self,+range:+NSRange(location:+0,+length:+characters.count))+>+0
++++}
}|code-block|syntax|javascript|79714|示例：|79715|"b@bb.pl".isValidEmail+//true
"b@bb".isValidEmail+//false|79716|您可以将以下扩展扩展到您需要的任何内容：isValidPhoneNumber、isValidPassword等。|offset|length|style|CODE|79717|entityMap^0|0|0|0|0|K|I|13|F|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@$M|X|N|Y|O|P]|$M|Z|N|10|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|R|$]]

Create simple extension:

<pre><code>extension NSRegularExpression {

 convenience init(pattern: String) {
 try! self.init(pattern: pattern, options: [])
 }
}

extension String {

 var isValidEmail: Bool {
 return isMatching(expression: NSRegularExpression(pattern: "^[A-Z0-9a-z\\._%+-]+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2,4}$"))
 }

 //MARK: - Private

 private func isMatching(expression: NSRegularExpression) -&gt; Bool {
 return expression.numberOfMatches(in: self, range: NSRange(location: 0, length: characters.count)) &gt; 0
 }
}
</code></pre>

Example:

<pre><code>"b@bb.pl".isValidEmail //true
"b@bb".isValidEmail //false
</code></pre>

You can extend following extension to anything you need: <code>isValidPhoneNumber</code>, <code>isValidPassword</code> etc...

blocks|key|79759|text|这是Swift+3中的一个扩展|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79760|extension+String+{
++++func+isValidEmail()+->+Bool+{
++++++++let+emailRegex+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,64}"
++++++++return+NSPredicate(format:+"SELF+MATCHES+%25@",+emailRegex).evaluate(with:+self)
++++}
}|code-block|syntax|javascript|79761|就像这样使用它：|79762|if+yourEmailString.isValidEmail()+{
++++//code+for+valid+email+address
}+else+{
++++//code+for+not+valid+email+address
}|79763|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Here is an extension in Swift 3

<pre><code>extension String {
 func isValidEmail() -&gt; Bool {
 let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
 return NSPredicate(format: "SELF MATCHES %@", emailRegex).evaluate(with: self)
 }
}
</code></pre>

Just use it like this:

<pre><code>if yourEmailString.isValidEmail() {
 //code for valid email address
} else {
 //code for not valid email address
}
</code></pre>

blocks|key|79800|text|或者您可以为UITextField的可选文本添加扩展名：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79801|使用方法：|79802|if++emailTextField.text.isEmailValid()+{
++++++print("email+is+valid")
}else{
++++++print("wrong+email+address")
}|code-block|syntax|javascript|79803|扩展名：|79804|extension+Optional+where+Wrapped+==+String+{
++++func+isEmailValid()+->+Bool{
++++++++guard+let+email+=+self+else+{+return+false+}
++++++++let+emailPattern+=+"[A-Za-z-0-9.-_]%2B@[A-Za-z0-9]%2B\\.[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
++++}
}|79805|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Or you can have extension for optional text of UITextField:

how to use:

<pre><code>if emailTextField.text.isEmailValid() {
 print("email is valid")
}else{
 print("wrong email address")
}
</code></pre>

extension:

<pre><code>extension Optional where Wrapped == String {
 func isEmailValid() -&gt; 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 &gt; 0 {
 return true
 }
 }catch{
 //error
 }
 return false
 }
}
</code></pre>

blocks|key|4586491|text|我喜欢创建扩展|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4586492|+++extension+String+{

func+isValidateEmail()+->+Bool+{
++++let+emailFormat+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,64}"
++++let+emailPredicate+=+NSPredicate(format:"SELF+MATCHES+%25@",+emailFormat)
++++return+emailPredicate.evaluate(with:+self)
}

}|code-block|syntax|javascript|4586493|用法：|4586494|if+emailid.text!.isValidateEmail()+==+false(){
+//do+what+ever+you+want+if+string+is+not+matched.

}|4586495|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I like to create extension 

<pre><code> extension String {

func isValidateEmail() -&gt; 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)
}

}
</code></pre>

usage:

<pre><code>if emailid.text!.isValidateEmail() == false(){
 //do what ever you want if string is not matched.

}
</code></pre>

blocks|key|79857|text|使用Swift+4.2|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79858|extension+String+{
++++func+isValidEmail()+->+Bool+{
++++++++let+regex+=+try?+NSRegularExpression(pattern:+"%5E(((([a-zA-Z]%7C\\d%7C[!#\\$%25&'\\*\\%2B\\-\\/=\\?\\%5E_`{\\%7C}~]%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])%2B(\\.([a-zA-Z]%7C\\d%7C[!#\\$%25&'\\*\\%2B\\-\\/=\\?\\%5E_`{\\%7C}~]%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])%2B)*)%7C((\\x22)((((\\x20%7C\\x09)*(\\x0d\\x0a))?(\\x20%7C\\x09)%2B)?(([\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f]%7C\\x21%7C[\\x23-\\x5b]%7C[\\x5d-\\x7e]%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])%7C(\\([\\x01-\\x09\\x0b\\x0c\\x0d-\\x7f]%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}]))))*(((\\x20%7C\\x09)*(\\x0d\\x0a))?(\\x20%7C\\x09)%2B)?(\\x22)))@((([a-zA-Z]%7C\\d%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])%7C(([a-zA-Z]%7C\\d%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])([a-zA-Z]%7C\\d%7C-%7C\\.%7C_%7C~%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*([a-zA-Z]%7C\\d%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.)%2B(([a-zA-Z]%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])%7C(([a-zA-Z]%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])([a-zA-Z]%7C\\d%7C-%7C_%7C~%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])*([a-zA-Z]%7C[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])))\\.?$",+options:+.caseInsensitive)
++++++++return+regex?.firstMatch(in:+self,+options:+[],+range:+NSMakeRange(0,+self.count))+!=+nil
++++}
++++func+isValidName()+->+Bool{
++++++++let+regex+=+try?+NSRegularExpression(pattern:+"%5E[\\p{L}\\.]{2,30}(?:+[\\p{L}\\.]{2,30}){0,2}$",+options:+.caseInsensitive)

++++++++return+regex?.firstMatch(in:+self,+options:+[],+range:+NSMakeRange(0,+self.count))+!=+nil
++++}+}|code-block|syntax|javascript|79859|并使用|79860|if+(textField.text?.isValidEmail())!+
++++{
++++++//+bla+bla
++++}
else+
++++{

++++}|79861|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Use of Swift 4.2

<pre><code>extension String {
 func isValidEmail() -&gt; Bool {
 let regex = try? NSRegularExpression(pattern: "^(((([a-zA-Z]|\\d|[!#\\$%&amp;'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\x{00A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}])+(\\.([a-zA-Z]|\\d|[!#\\$%&amp;'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\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}])))\\.?$", options: .caseInsensitive)
 return regex?.firstMatch(in: self, options: [], range: NSMakeRange(0, self.count)) != nil
 }
 func isValidName() -&gt; Bool{
 let regex = try? NSRegularExpression(pattern: "^[\\p{L}\\.]{2,30}(?: [\\p{L}\\.]{2,30}){0,2}$", options: .caseInsensitive)

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

And used

<pre><code>if (textField.text?.isValidEmail())! 
 {
 // bla bla
 }
else 
 {

 }
</code></pre>

blocks|key|79909|text|这是当前Swiftmailer中提供的一种非常简单的方法。大多数其他的答案都是陈旧的，并重新发明了轮子。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79910|根据Swiftmailer文档：https://swiftmailer.symfony.com/docs/messages.html#quick-reference|offset|length|79911|use+Egulias\EmailValidator\EmailValidator;
use+Egulias\EmailValidator\Validation\RFCValidation;

$validator+=+new+EmailValidator();
$validator->isValid("example@example.com",+new+RFCValidation());+//true|code-block|syntax|javascript|79912|这是迄今为止最简单和最健壮的方法，imo。只需通过Composer安装Egulias\EmailValidator库，它应该已经作为SwiftMailer的依赖项引入了。|79913|entityMap|0|LINK|mutability|MUTABLE|url|https://swiftmailer.symfony.com/docs/messages.html#quick-reference^0|0|G|1U|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@$D|W|E|X|1|Y]]|A|$]]|$1|F|3|G|5|H|7|Z|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

Here is a very simple way available in current Swiftmailer. Most of the other answers are old and reinvent the wheel.

As per Swiftmailer documentation:
<a href="https://swiftmailer.symfony.com/docs/messages.html#quick-reference" rel="nofollow noreferrer">https://swiftmailer.symfony.com/docs/messages.html#quick-reference</a>

<pre><code>use Egulias\EmailValidator\EmailValidator;
use Egulias\EmailValidator\Validation\RFCValidation;

$validator = new EmailValidator();
$validator-&gt;isValid("example@example.com", new RFCValidation()); //true
</code></pre>

This is by far the simplest and most robust approach, imo. Just install via Composer the Egulias\EmailValidator library which should already be brought in as a dependency of SwiftMailer anyway.

blocks|key|4586609|text|对于任何还在寻找答案的人，请看一下下面的框架；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4586610|ATGValidator|offset|length|4586611|它是一个基于规则的验证框架，可以处理大多数开箱即用的验证。最重要的是，它有form+validator，支持同时验证多个文本字段。|style|CODE|4586612|要验证电子邮件字符串，请使用以下命令；|4586613|"abcd.hhs@some.com".satisfyAll(rules:+[StringRegexRule.email]).status|code-block|syntax|javascript|4586614|如果你想验证一封来自文本字段的电子邮件，试试下面的代码；|4586615|textfield.validationRules+=+[StringRegexRule.email]
textfield.validationHandler+=+{+result+in
++++//+This+block+will+be+executed+with+relevant+result+whenever+validation+is+done.
++++print(result.status,+result.errors)
}
//+Below+line+is+to+manually+trigger+validation.
textfield.validateTextField()|4586616|如果要在文本字段中键入或将焦点切换到另一个字段时进行验证，请添加以下行之一；|4586617|textfield.validateOnInputChange(true)
//+or
textfield.validateOnFocusLoss(true)|4586618|有关更多使用案例，请查看link上的自述文件。|4586619|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/altayer-digital/ATGValidator|1^0|0|0|C|0|0|11|E|0|0|0|0|0|0|0|C|4|1|0^^$0|@$1|2|3|4|5|6|7|19|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1A|8|@]|9|@$D|1B|E|1C|1|1D]]|A|$]]|$1|F|3|G|5|6|7|1E|8|@$D|1F|E|1G|H|I]]|9|@]|A|$]]|$1|J|3|K|5|6|7|1H|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|1I|8|@]|9|@]|A|$O|P]]|$1|Q|3|R|5|6|7|1J|8|@]|9|@]|A|$]]|$1|S|3|T|5|N|7|1K|8|@]|9|@]|A|$O|P]]|$1|U|3|V|5|6|7|1L|8|@]|9|@]|A|$]]|$1|W|3|X|5|N|7|1M|8|@]|9|@]|A|$O|P]]|$1|Y|3|Z|5|6|7|1N|8|@]|9|@$D|1O|E|1P|1|1Q]]|A|$]]|$1|10|3|-4|5|6|7|1R|8|@]|9|@]|A|$]]]|11|$12|$5|13|14|15|A|$16|17]]|18|$5|13|14|15|A|$16|17]]]]

For anyone who is still looking for an answer to this, please have a look at the following framework;

<a href="https://github.com/altayer-digital/ATGValidator" rel="nofollow noreferrer">ATGValidator</a>

It is a rule based validation framework, which handles most of the validations out of box. And top it all, it has <code>form validator</code> which supports validation of multiple textfields at the same time.

For validating an email string, use the following;

<pre><code>"abcd.hhs@some.com".satisfyAll(rules: [StringRegexRule.email]).status
</code></pre>

If you want to validate an email from textfield, try below code;

<pre><code>textfield.validationRules = [StringRegexRule.email]
textfield.validationHandler = { result in
 // This block will be executed with relevant result whenever validation is done.
 print(result.status, result.errors)
}
// Below line is to manually trigger validation.
textfield.validateTextField()
</code></pre>

If you want to validate it while typing in textfield or when focus is changed to another field, add one of the following lines;

<pre><code>textfield.validateOnInputChange(true)
// or
textfield.validateOnFocusLoss(true)
</code></pre>

Please check the readme file at the <a href="https://github.com/altayer-digital/ATGValidator" rel="nofollow noreferrer">link</a> for more use cases.

blocks|key|79995|text|Swift+5-可伸缩验证层|type|unstyled|depth|inlineStyleRanges|entityRanges|data|79996|使用这一层，您可以轻松地对任何文本字段进行令人惊叹的验证。|79997|只需遵循以下流程即可。|79998|1.添加这些枚举：|79999|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"
++++++++}
++++}
}|code-block|syntax|javascript|80000|2.将此功能添加到String|offset|length|style|CODE|80001|extension+String
{
++++//+MARK:-+Properties

++++var+isValidEmail:+Bool
++++{
++++++++let+emailFormat+=+"[A-Z0-9a-z._%25%2B-]%2B@[A-Za-z0-9.-]%2B\\.[A-Za-z]{2,64}"
++++++++let+emailPredicate+=+NSPredicate(format:"SELF+MATCHES+%25@",+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
++++}
}|80002|3.向UITextField添加以下功能|80003|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+%2B+6,+y:+center.y))
++++++++animation.toValue+=+NSValue(cgPoint:+CGPoint(x:+center.x+-+6,+y:+center.y))
++++++++layer.add(animation,+forKey:+"position")
++++}
}|80004|用法|80005|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+...
++++++++}
++++}
}|80006|entityMap^0|0|0|0|0|0|9|6|0|0|3|B|0|0|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|15|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|16|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|17|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|18|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|19|8|@$O|1A|P|1B|Q|R]]|9|@]|A|$]]|$1|S|3|T|5|J|7|1C|8|@]|9|@]|A|$K|L]]|$1|U|3|V|5|6|7|1D|8|@$O|1E|P|1F|Q|R]]|9|@]|A|$]]|$1|W|3|X|5|J|7|1G|8|@]|9|@]|A|$K|L]]|$1|Y|3|Z|5|6|7|1H|8|@]|9|@]|A|$]]|$1|10|3|11|5|J|7|1I|8|@]|9|@]|A|$K|L]]|$1|12|3|-4|5|6|7|1J|8|@]|9|@]|A|$]]]|13|$]]

<h1>Swift 5 - Scalable Validation Layer</h1>
Using this layer you will get amazing validations over any text field easily.
Just follow the following process.
<h2>1. Add these enums:</h2>
<pre><code>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 &quot;Please kindly write a valid email&quot; 
 case .invalidUserName:
 return &quot;Please kindly write a valid user name&quot;
 }
 }
}
</code></pre>
<h2>2. Add this functionality to <code>String</code>:</h2>
<pre><code>extension String
{
 // MARK:- Properties

 var isValidEmail: Bool
 {
 let emailFormat = &quot;[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}&quot;
 let emailPredicate = NSPredicate(format:&quot;SELF MATCHES %@&quot;, 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
 }
}
</code></pre>
<h2>3. Add the following functionality to <code>UITextField</code>:</h2>
<pre><code>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: &quot;position&quot;)
 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: &quot;position&quot;)
 }
}
</code></pre>
<h1>Usage</h1>
<pre><code>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() -&gt; 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 ...
 }
 }
}
</code></pre>

blocks|key|80036|text|这是一个最新的游乐场兼容版本，它使用标准库，因此您不必维护regex：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|80037|import+Foundation

func+isValid(email:+String)+->+Bool+{
++do+{
++++let+detector+=+try+NSDataDetector(types:+NSTextCheckingResult.CheckingType.link.rawValue)
++++let+range+=+NSRange(location:+0,+length:+email.count)
++++let+matches+=+detector.matches(in:+email,+options:+.anchored,+range:+range)
++++guard+matches.count+==+1+else+{+return+false+}
++++return+matches[0].url?.scheme+==+"mailto"
++}+catch+{
++++return+false
++}
}

extension+String+{
++var+isValidEmail:+Bool+{
++++isValid(email:+self)
++}
}

let+email+=+"test@mail.com"
isValid(email:+email)+//+prints+'true'
email.isValidEmail+//+prints+'true'|code-block|syntax|javascript|80038|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here's an up to date playground compatible version that uses the standard library so you don't have to maintain a regex:
<pre class="lang-swift prettyprint-override"><code>import Foundation

func isValid(email: String) -&gt; Bool {
 do {
 let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
 let range = NSRange(location: 0, length: email.count)
 let matches = detector.matches(in: email, options: .anchored, range: range)
 guard matches.count == 1 else { return false }
 return matches[0].url?.scheme == &quot;mailto&quot;
 } catch {
 return false
 }
}

extension String {
 var isValidEmail: Bool {
 isValid(email: self)
 }
}

let email = &quot;test@mail.com&quot;
isValid(email: email) // prints 'true'
email.isValidEmail // prints 'true'
</code></pre>

Does anyone know how to validate an e-mail address in Swift? I found this code:

<pre><code>- (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;
 }
}
</code></pre>

but I can't translate it to Swift.

How to validate an e-mail address in swift?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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有人知道如何在Swift中验证电子邮件地址吗？我找到了这段代码：- (BOOL) validEmail:(NSString*) emailString {    if([emailString length]==0){        return NO;    }    NSString *regExPattern =...

问如何在swift中验证电子邮件地址？
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