Model类中可以添加的验证标记：

1. 必填字段

[Required]

public string FirstName { get; set; }

2. 字段长度

至多n位：

[StringLength(160)]

public string FirstName { get; set; }

要求至少n位：

[StringLength(160, MinimumLength=3)]

public string FirstName { get; set; }

3. 正则验证

[RegularExpression(@”[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}”)]

public string Email { get; set; }

4. 范围

[Range(35,44)]

public int Age { get; set; }

小数的情况：

[Range(typeof(decimal), “0.00”, “49.99”)]

public decimal Price { get; set; }

5. 服务端参与的验证

[Remote(“CheckUserName”, “Account”)]

public string UserName { get; set; }

然后在AccountController里指定一个CheckUserName方法：

public JsonResult CheckUserName(string username){    var result = Membership.FindUsersByName(username).Count == 0;    return Json(result, JsonRequestBehavior.AllowGet);}

6. 比较

[RegularExpression(@”[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}”)]

public string Email { get; set; }

[Compare(“Email”)]

public string EmailConfirm { get; set; }

7. 自定义错误消息

正则：

[RegularExpression(@”[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}”,

                   ErrorMessage=”Email doesn’t look like a valid email address.”)]

public string Email { get; set; }

普通文本：

[Required(ErrorMessage=”Your last name is required”)]

[StringLength(160, ErrorMessage=”Your last name is too long”)]

public string LastName { get; set; }

占位符：

[Required(ErrorMessage=”Your {0} is required.”)]

[StringLength(160, ErrorMessage=”{0} is too long.”)]

public string LastName { get; set; }

三、后台Action的写法

Action里要做的有两件事：判断ModelState是否合法、添加错误消息。MVC3模板自带的登录Action如下：

[HttpPost]public ActionResult LogOn(LogOnModel model, string returnUrl){    if (ModelState.IsValid)    {        if (Membership.ValidateUser(model.UserName, model.Password))        {            FormsAuthentication.SetAuthCookie(model.UserName, model.RememberMe);            if (Url.IsLocalUrl(returnUrl) && returnUrl.Length > 1 && returnUrl.StartsWith("/")                && !returnUrl.StartsWith("//") && !returnUrl.StartsWith("/\\"))            {                return Redirect(returnUrl);            }            else            {                return RedirectToAction("Index", "Home");            }        }        else        {            ModelState.AddModelError("", "The user name or password provided is incorrect.");        }    }     // If we got this far, something failed, redisplay form    return View(model);}

MVC Model验证