blocks|key|351050|text|也添加一个必需的字段验证器-我认为regex验证器只有在字段中有文本需要查看时才会触发。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|351051|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Add a required field validator as well - I think the regex validator will only fire if there is text in the field to look at.

blocks|key|351066|text|其中一个解决方案(不是最好的)是实现一些正则表达式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|351067|%5E([0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)%2B[a-zA-Z]{2,9})$|code-block|syntax|javascript|351068|示例:+someone@example.com|351069|但实际上，很难编写和维护一个好的电子邮件验证regexp。您不应该100%25信任您的正则表达式。你可以在互联网上找到几篇关于这个困难的文章：|351070|351071|It's+Impossible+to+Validate+an+Email+Address+(elliot.land)+-+discussion+on+Hacker+News|unordered-list-item|offset|length|351072|Stop+Validating+Email+Addresses+With+Regex|351073|Email+Address+Regular+Expression+That+99.99%25+Works.|351074|351075|entityMap|0|LINK|mutability|MUTABLE|url|https://news.ycombinator.com/item?id=11414749|1|https://davidcel.is/posts/stop-validating-email-addresses-with-regex/|2|http://emailregex.com/^0|0|0|0|0|0|0|2E|0|0|0|16|1|0|0|1F|2|0|0^^$0|@$1|2|3|4|5|6|7|17|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|18|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|19|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|1A|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|1C|8|@]|9|@$O|1D|P|1E|1|1F]]|A|$]]|$1|Q|3|R|5|N|7|1G|8|@]|9|@$O|1H|P|1I|1|1J]]|A|$]]|$1|S|3|T|5|N|7|1K|8|@]|9|@$O|1L|P|1M|1|1N]]|A|$]]|$1|U|3|-4|5|6|7|1O|8|@]|9|@]|A|$]]|$1|V|3|-4|5|6|7|1P|8|@]|9|@]|A|$]]]|W|$X|$5|Y|Z|10|A|$11|12]]|13|$5|Y|Z|10|A|$11|14]]|15|$5|Y|Z|10|A|$11|16]]]]

One of the solutions (not a best one) is to implement some regular expression:

<pre><code>^([0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,9})$
</code></pre>

Sample: someone@example.com

But actually, it's very hard to write and maintain a good email validation regexp. You shouldn't trust 100% your regex. You can find several articles about that difficulty on the Internet:

<ul>
<li><a href="https://news.ycombinator.com/item?id=11414749" rel="nofollow noreferrer">It's Impossible to Validate an Email Address (elliot.land) - discussion on Hacker News</a></li>
<li><a href="https://davidcel.is/posts/stop-validating-email-addresses-with-regex/" rel="nofollow noreferrer">Stop Validating Email Addresses With Regex</a></li>
<li><a href="http://emailregex.com/" rel="nofollow noreferrer">Email Address Regular Expression That 99.99% Works.</a></li>
</ul>

blocks|key|3071503|text|如果您想将此字段视为必填字段，那么最好使用RequiredFieldValidator。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3071504|++++<asp:RequiredFieldValidator+ID="reqEmail"+ControlToValidate="txtEmail"+runat="server"+ErrorMessage="Email+address+required"></asp:RequiredFieldValidator>|code-block|syntax|javascript|3071505|谢谢,|3071506|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

If you want to treat this field as required one then it is better go for RequiredFieldValidator.

<pre><code> &lt;asp:RequiredFieldValidator ID="reqEmail" ControlToValidate="txtEmail" runat="server" ErrorMessage="Email address required"&gt;&lt;/asp:RequiredFieldValidator&gt;
</code></pre>

Thanks,

blocks|key|1095720|text|您需要使用额外的验证器-+asp:RequiredFieldValidator|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1095721|<asp:RequiredFieldValidator+runat="server"+ControlToValidate="txtEmail"+ErrorMessage="Message!"+/>|code-block|syntax|javascript|1095722|任何基于BaseValidator的ASP.NET+2.0验证器(当然除了RequiredFieldValidator本身)都不会检查指定的字段是否为空。|1095723|顺便说一句，要使定制的UserControl能够通过这样的验证器进行检查，请使用|1095724|[System.Web.UI.ValidationProperty("PropertyName")]|1095725|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/ru-ru/library/system.web.ui.mobilecontrols.requiredfieldvalidator%2528VS.90%2529.aspx|1|http://msdn.microsoft.com/ru-ru/library/system.web.ui.mobilecontrols.basevalidator%2528VS.90%2529.aspx^0|D|Q|D|Q|0|0|0|4|D|4|D|1|0|B|B|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@$9|13|A|14|1|15]]|E|$]]|$1|F|3|G|5|H|7|16|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|17|8|@$9|18|A|19|B|C]]|D|@$9|1A|A|1B|1|1C]]|E|$]]|$1|M|3|N|5|6|7|1D|8|@$9|1E|A|1F|B|C]]|D|@]|E|$]]|$1|O|3|P|5|H|7|1G|8|@]|D|@]|E|$I|J]]|$1|Q|3|-4|5|6|7|1H|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]|Y|$5|T|U|V|E|$W|Z]]]]

You need to use an additional validator - <a href="http://msdn.microsoft.com/ru-ru/library/system.web.ui.mobilecontrols.requiredfieldvalidator%28VS.90%29.aspx" rel="nofollow noreferrer"><code>asp:RequiredFieldValidator</code></a>

<pre><code>&lt;asp:RequiredFieldValidator runat="server" ControlToValidate="txtEmail" ErrorMessage="Message!" /&gt;
</code></pre>

Any of ASP.NET 2.0 validators based on <a href="http://msdn.microsoft.com/ru-ru/library/system.web.ui.mobilecontrols.basevalidator%28VS.90%29.aspx" rel="nofollow noreferrer"><code>BaseValidator</code></a> (except RequiredFieldValidator itself of course) doesn't checks specified field to be empty.

Btw, to make custom <code>UserControl</code> being able to be checked with such validators, use

<pre><code>[System.Web.UI.ValidationProperty("PropertyName")]
</code></pre>

blocks|key|1095762|text|你不能做一些像这样的东西吗|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1095763|if+(txtEmail.Text.Trim().length+>+0)+then
+++++++validate|code-block|syntax|javascript|1095764|我认为由于正则表达式相当复杂，任何可以在正则表达式之外完成的操作都应该在正则表达式之外完成，这应该会使代码更具可读性，但这只是我的观点。|1095765|你的正则表达式相当复杂，你应该找一个更简单的here。不管怎样，你可以这样做：%5E(regex){1}$|offset|length|1095766|entityMap|0|LINK|mutability|MUTABLE|url|http://www.regular-expressions.info/email.html^0|0|0|0|M|4|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|X|8|@]|9|@$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]]]]

Can't you make something like 

<pre><code>if (txtEmail.Text.Trim().length &gt; 0) then
 validate
</code></pre>

I think that since regular expressions are rather complex, anything that can be done outside the regular expression should be done outside the regular expression, this should make the code more readable, but that is just me.

Your regular expression is quite complex, <a href="http://www.regular-expressions.info/email.html" rel="nofollow noreferrer">here</a> you should find a simpler one. 
Anyways, what you can do is something like this: ^(regex){1}$

blocks|key|1095806|text|另一种选择是使用验证器CustomValidator，将其ValidateEmptyText设置为validator+True，对于电子邮件地址验证，您可以使用将在.net的验证器的ClientValidationFunction属性中指定的函数。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|1095807|entityMap^0|B|F|T|H|2J|O|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|O|8|@]|D|@]|E|$]]]|G|$]]

Another choice is to use .net CustomValidator, set its ValidateEmptyText to True, and for email address validation you can use a JavaScript function which will be specified in ClientValidationFunction property of validator.

blocks|key|350523|text|void+Page_Load(Object+sender,+EventArgs+e)
{
++++string+uNameExpr+=+"%5E[a-zA-Z](.{1,9})$";
++++string+phoneExpr+=+
++++++++"((\$\\d{3}\$+?)%7C(\\d{3}-))?\\d{3}-\\d{4}";

++++//+Define+validation+expressions.
++++RegExprVal1.ValidationExpression+=+uNameExpr;
++++RegExprVal2.ValidationExpression+=+phoneExpr;

++++ReqFldVal1.Text+=+"User+name+is+required";
++++RegExprVal1.Text+=+"Must+be+between+2+to+10+characters";
++++RegExprVal2.Text+=+"Please+provide+a+valid+number:+(425)+555-0187";
++++//+ErrorMessages+appear+in+ValidationSummary.
++++RegExprVal1.ErrorMessage+=+"Incorrect+UserName+format.+Name"+%2B
++++++++"+can+be+2+to+10+characters+long";
++++ReqFldVal1.ErrorMessage+=+"User+name+required";
++++RegExprVal2.ErrorMessage+=+
++++++++"Please+provide+a+valid+number:+(000)+000-0000";
}

void+OnCmdClick(Object+sender,+EventArgs+e)
{
++++if+(Page.IsValid)
++++{
++++++++ActiveForm+=+Form2;
++++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|350524|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>void Page_Load(Object sender, EventArgs e)
{
 string uNameExpr = "^[a-zA-Z](.{1,9})$";
 string phoneExpr = 
 "((\$\\d{3}\$ ?)|(\\d{3}-))?\\d{3}-\\d{4}";

 // Define validation expressions.
 RegExprVal1.ValidationExpression = uNameExpr;
 RegExprVal2.ValidationExpression = phoneExpr;

 ReqFldVal1.Text = "User name is required";
 RegExprVal1.Text = "Must be between 2 to 10 characters";
 RegExprVal2.Text = "Please provide a valid number: (425) 555-0187";
 // ErrorMessages appear in ValidationSummary.
 RegExprVal1.ErrorMessage = "Incorrect UserName format. Name" +
 " can be 2 to 10 characters long";
 ReqFldVal1.ErrorMessage = "User name required";
 RegExprVal2.ErrorMessage = 
 "Please provide a valid number: (000) 000-0000";
}

void OnCmdClick(Object sender, EventArgs e)
{
 if (Page.IsValid)
 {
 ActiveForm = Form2;
 }
}
</code></pre>

blocks|key|3071719|text|这只需在System.Text.RegularExpressions中使用Regex类即可完成|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3071720|private+bool+ValidateEmail()
{
++++string+email+=+txtemail.Text;
++++Regex+regex+=+new+Regex(@"%5E([\w\.\-]%2B)@([\w\-]%2B)((\.(\w){2,3})%2B)$");
++++Match+match+=+regex.Match(email);
++++if+(match.Success)
+++++++return+true;
++++else
+++++++return+false;
}|code-block|syntax|javascript|3071721|entityMap^0|4|U|11|5|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

This can be done with simply using <code>Regex</code> class in <code>System.Text.RegularExpressions</code>:

<pre><code>private bool ValidateEmail()
{
 string email = txtemail.Text;
 Regex regex = new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$");
 Match match = regex.Match(email);
 if (match.Success)
 return true;
 else
 return false;
}
</code></pre>

Can anyone correct the expression below to also not allow blank field?

<pre><code>&lt;asp:RegularExpressionValidator ID="expEmail" runat="server" ControlToValidate="txtEmail" ErrorMessage="valid email address required" ValidationExpression="^([a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]){1,70}$"&gt;&lt;/asp:RegularExpressionValidator&gt;
</code></pre>

Email Regular Expression Validation

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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是否有人可以更正下面的表达式，使其也不允许空白字段？<asp:RegularExpressionValidator ID="expEmail" runat="server" ControlToValidate="txtEmail" ErrorMessage="valid email address required" ...

问电子邮件正则表达式验证
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