MVC验证05-自定义验证规则、验证2个属性值不等

本文体验2个属性值不等。即当一个属性输入值，另外一个属性输入的值不能和第一个属性值相等。相关文章包括：

MVC验证01-基础、远程验证  
MVC验证02-自定义验证规则、邮件验证  
MVC验证03-自定义验证规则、禁止输入某些值  
MVC验证04-自定义验证规则、日期范围验证 

  自定义验证特性，继承ValidationAttribute并实现IClientValidatable

这次重写了基类的IsValid()方法的另外一个重载，因为该重载包含了验证上下文ValidationContext，从中可以获取属性及属性值。

using System.ComponentModel.DataAnnotations;
using System.Globalization;
using System.Web.Mvc;

namespace MvcValidation.Extension
{
    public class NotEqualToAttribute : ValidationAttribute,IClientValidatable
    {
        public string OtherProperty { get; set; }

        public NotEqualToAttribute(string otherProperty)
        {
            OtherProperty = otherProperty;
        }

        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            //从验证上下文中可以获取我们想要的的属性
            var property = validationContext.ObjectType.GetProperty(OtherProperty);
            if (property == null)
            {
                return new ValidationResult(string.Format(CultureInfo.CurrentCulture, "{0} 不存在", OtherProperty));
            }

            //获取属性的值
            var otherValue = property.GetValue(validationContext.ObjectInstance, null);
            if (object.Equals(value, otherValue))
            {
                return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
            }
            return null;
        }

        public System.Collections.Generic.IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
        {
            var rule = new ModelClientValidationRule
            {
                ValidationType = "notequalto",
                ErrorMessage = FormatErrorMessage(metadata.GetDisplayName())
            };
            rule.ValidationParameters["other"] = OtherProperty;
            yield return rule;
        }
    }
}

  View model

[NotEqualTo("UserName", ErrorMessage = "不能与用户名的值相同")]用来比较属性UserName的值。

 public class RegisterModel
    {
        [Required]
        [StringLength(6, MinimumLength = 2)] //加
        [Display(Name = "用户名")]
        //[Remote("CheckUserName","Validate", ErrorMessage = "远程验证用户名失败")]
        [NoInput("demo,jack",ErrorMessage = "不能使用此名称")]
        public string UserName { get; set; }

        [Required]
        [DataType(DataType.EmailAddress)]
        [Display(Name = "邮件")]
        //[Email]
        public string Email { get; set; }

        [Required]
        [StringLength(100, ErrorMessage = "{0}栏位最少{2}个字，最多{1}个字", MinimumLength = 6)]
        [DataType(DataType.Password)]
        [Display(Name = "密码")]
        public string Password { get; set; }

        [DataType(DataType.Password)]
        [Display(Name = "确认密码")]
        [System.ComponentModel.DataAnnotations.Compare("Password", ErrorMessage = "密码和确认密码不匹配。")]
        public string ConfirmPassword { get; set; }

        [NotEqualTo("UserName", ErrorMessage = "不能与用户名的值相同")]
        public string OtherName { get; set; }
    }

  扩展jquery的验证，jQuery.validator.noteaualto.js

jQuery.validator.addMethod('notEaualTo', function(value, element, param) {
    //意思是表单值为空时也能通过验证
    //但，如果表单有值，就必须满足||后面的条件，否则返回false
    return this.optional(element) || value != $(param).val();
});

//第一个参数是jquery验证扩展方法名
//第二个参数与rule.ValidationParameters["other"]中的key对应
//option是指ModelClientValidationRule对象实例
jQuery.validator.unobtrusive.adapters.add('notequalto', ['other'], function(options) {
    options.rules['notEqualTo'] = '#' + options.params.other;
    if (options.message) {
        options.messages['notEqualTo'] = options.message;
    }
});

  Register.cshtml视图

@model MvcValidation.Models.RegisterModel
@{
    ViewBag.Title = "注册";
}

<hgroup class="title">
    <h1>@ViewBag.Title.</h1>
    <h2>创建新帐户。</h2>
</hgroup>

@using (Html.BeginForm()) {
    @Html.AntiForgeryToken()
    @Html.ValidationSummary()

    <fieldset>
        <legend>注册表单</legend>
        <ol>
            <li>
                @Html.LabelFor(m => m.UserName)
                @Html.TextBoxFor(m => m.UserName)
            </li>
            <li>
                @Html.LabelFor(m => m.Email)
                @Html.TextBoxFor(m => m.Email)
            </li>
            <li>
                @Html.LabelFor(m => m.Password)
                @Html.PasswordFor(m => m.Password)
            </li>
            <li>
                @Html.LabelFor(m => m.ConfirmPassword)
                @Html.PasswordFor(m => m.ConfirmPassword)
            </li>
            <li>
                @Html.LabelFor(m => m.OtherName)
                @Html.TextBoxFor(m => m.OtherName)
            </li>
        </ol>
        <input type="submit" value="注册" />
    </fieldset>
}

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
    <script src="~/Scripts/jQuery.validator.noteaualto.js"></script>
}

效果：