在简单了解了Unobtrusive JavaScript形式的验证在jQuery中的编程方式之后，我们来介绍ASP.NET MVC是如何利用它实现客户端验证的。服务端验证最终实现在相应的ModelValidator中，而最终的验证规则定义在相应的ValidationAttribute中；而客户端验证规则通过HtmlHelper<TModel>相应的扩展方法（比如TextBoxFor、EditorFor和EdidtorForModel等）出现在生成的被验证HTML元素中。毫无疑问，服务端验证和客户端验证必须采用相同的验证规则，那么通过应用ValidationAttribute特性定义的验证规则也同样体现在基于客户端验证规则的HTML上。[本文已经同步到《How ASP.NET MVC Works?》中]
ASP.NET MVC默然采用基于ValidationAttribute特性的声明式Model验证，服务端验证最终实现在两个重写的IsValid方法中。对于客户端验证，ASP.NET MVC对jQuery的验证插件进行了扩展，实现了另一种不同的内联方式是我们 可以将验证规则定义在被验证输入元素的属性中。为了让客户端和服务端采用相同的验证规则，应用在Model类型某个属性上的ValidationAttribute特性最终会体现在目标属性对应的HTML元素上。
<div id="codeSnippet" style=‘padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: rgb(244, 244, 244);‘><pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: white;‘>
1:publicclass Contact <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: rgb(244, 244, 244);‘>
2: { <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: white;‘>
3: [DisplayName(
"姓名")] <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: rgb(244, 244, 244);‘>
4: [Required(ErrorMessage =
"请输入{0}!")] <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: white;‘>
5: [StringLength(8, ErrorMessage=
"作为{0}字符串长度不能超过{1}!")] <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: rgb(244, 244, 244);‘>
6:publicstring Name { get; set; } <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: white;‘>
7: <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: rgb(244, 244, 244);‘>
8: [DisplayName(
"电子邮箱地址")] <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: white;‘>
9: [RegularExpression(
@"^\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}$",ErrorMessage=
"请输入正确的电子邮箱地址！")] <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: rgb(244, 244, 244);‘>
10:publicstring EmailAddress { get; set; } <pre style=‘margin: 0em; padding: 0px; width: 100%; text-align: left; color: black; line-height: 12pt; overflow: visible; font-family: "Courier New", courier, monospace; font-size: 8pt; direction: ltr; background-color: white;‘>
11: }
