ASP.NET MVC中的验证

1.简单验证

在ASP.Net MVC中，验证是在Controller层，而错误呈现是在View层，Controller层是通过ModelState属性进行验证的,ModelState的状态是通过AddModelError()方法进行 添加的。

而在View层，是通过Html的辅助方法进行呈现的，这两个辅助方法分别是

• Html.ValidationMessage()
• Html.ValidationSummary()

 

Controller层的简单验证
        [AcceptVerbs(HttpVerbs.Post)]
         public  ActionResult Create([Bind(Exclude = " CustomerId " )] Customer customer)
        {
             if  (customer.CompanyName.Length  ==   0 )
            {
                ModelState.AddModelError( " CompanyName " ,  " CompanyName不能为空 " );
            }
             if  (customer.EmailAddress.Length  ==   0 )
            {
                ModelState.AddModelError( " EmailAddress " ,  " EmailAddress不能为空 " );
            }
             if  ( ! ModelState.IsValid)
            {
                 return  View();
            }
             try
            {
                _entities.AddToCustomer(customer);
                _entities.SaveChanges();
                 return  RedirectToAction( " Index " );
            }
             catch
            {
                 return  View();
            }
        }

 

View层的Html辅助方法Html.ValidationMessage()与Html.ValidationSummary()
<% @ Page Title = ""  Language = " C# "  MasterPageFile = " ~/Views/Shared/Site.Master "  Inherits = " System.Web.Mvc.ViewPage<MvcApplication4.Models.Customer> "   %>

< asp:Content  ID ="Content1"  ContentPlaceHolderID ="TitleContent"  runat ="server" >
    Create
</ asp:Content >

< asp:Content  ID ="Content2"  ContentPlaceHolderID ="MainContent"  runat ="server" >

     < h2 > Create </ h2 >

     <% =  Html.ValidationSummary( " Create was unsuccessful. Please correct the errors and try again. " )  %>

     <%  using (Html.BeginForm()) { %>

         < fieldset >
             < legend > Fields </ legend >
             < p >
                 < label  for ="NameStyle" > NameStyle: </ label >
                 <% =  Html.TextBox( " NameStyle " )  %>
                 <% =  Html.ValidationMessage( " NameStyle " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="Title" > Title: </ label >
                 <% =  Html.TextBox( " Title " )  %>
                 <% =  Html.ValidationMessage( " Title " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="FirstName" > FirstName: </ label >
                 <% =  Html.TextBox( " FirstName " )  %>
                 <% =  Html.ValidationMessage( " FirstName " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="MiddleName" > MiddleName: </ label >
                 <% =  Html.TextBox( " MiddleName " )  %>
                 <% =  Html.ValidationMessage( " MiddleName " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="LastName" > LastName: </ label >
                 <% =  Html.TextBox( " LastName " )  %>
                 <% =  Html.ValidationMessage( " LastName " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="Suffix" > Suffix: </ label >
                 <% =  Html.TextBox( " Suffix " )  %>
                 <% =  Html.ValidationMessage( " Suffix " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="CompanyName" > CompanyName: </ label >
                 <% =  Html.TextBox( " CompanyName " )  %>
                 <% =  Html.ValidationMessage( " CompanyName " ,  " CompanyName不能为空 " )  %>
             </ p >
             < p >
                 < label  for ="SalesPerson" > SalesPerson: </ label >
                 <% =  Html.TextBox( " SalesPerson " )  %>
                 <% =  Html.ValidationMessage( " SalesPerson " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="EmailAddress" > EmailAddress: </ label >
                 <% =  Html.TextBox( " EmailAddress " )  %>
                 <% =  Html.ValidationMessage( " EmailAddress " ,  " EmailAddress不能为空 " )  %>
             </ p >
             < p >
                 < label  for ="Phone" > Phone: </ label >
                 <% =  Html.TextBox( " Phone " )  %>
                 <% =  Html.ValidationMessage( " Phone " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="PasswordHash" > PasswordHash: </ label >
                 <% =  Html.TextBox( " PasswordHash " )  %>
                 <% =  Html.ValidationMessage( " PasswordHash " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="PasswordSalt" > PasswordSalt: </ label >
                 <% =  Html.TextBox( " PasswordSalt " )  %>
                 <% =  Html.ValidationMessage( " PasswordSalt " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="rowguid" > rowguid: </ label >
                 <% =  Html.TextBox( " rowguid " )  %>
                 <% =  Html.ValidationMessage( " rowguid " ,  " * " )  %>
             </ p >
             < p >
                 < label  for ="ModifiedDate" > ModifiedDate: </ label >
                 <% =  Html.TextBox( " ModifiedDate " )  %>
                 <% =  Html.ValidationMessage( " ModifiedDate " ,  " * " )  %>
             </ p >
             < p >
                 < input  type ="submit"  value ="Create"   />
             </ p >
         </ fieldset >

     <%  }  %>

     < div >
         <% = Html.ActionLink( " Back to List " ,  " Index " )  %>
     </ div >

</ asp:Content >

如果使用Entityframework生成的Model，数据库设计时为不为空，那么生成的Model层该字段的Nullable属性就为false，即使在Controller没有做简单验证，在View层也会做是否为空的判断的。 

 

2.使用IDataErrorInfo Interface

 IDataErrorInfo接口的定义比较简单：

 

public interface IDataErrorInfo


    {


        string this[string columnName] { get; }





        string Error { get; }


    }

 

 

 使用IDataErrorInfo Interface的步骤如下：

• 针对Model，创建一个Partial类
• 添加OnChanging和OnChanged Partial方法
• 实现IDataErrorInfo接口

 

使用IdataErrorInfo
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel;

namespace MvcApplication4.Models
{
    public partial class Customer:IDataErrorInfo
    {
        private Dictionary < string , string >  _errors = new Dictionary < string , string > ();
        
        partial void OnCompanyNameChanging(string value)
        {
            if (value.Trim().Length == 0)
            {
                _errors.Add("CompanyName", "CompanyName is required");
            }
        }

        public string Error
        {
            get
            {
                return string.Empty;
            }
        }

        public string this[string columnName]
        {
            get
            {
                if (_errors.ContainsKey(columnName))
                {
                    return _errors[columnName];
                }
                return string.Empty;
            }
        }
    }
}

3.使用Data Annotation Validators

• 下载Data Annotations Model Binder sample ，下载地址在http://aspnet.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=24471
• 添加对 Microsoft.Web.Mvc.DataAnnotations.dll和System.ComponentModel.DataAnnotations.dll 的引用
• 在Global.asax.cs中的Application_Start()方法中配置
• 使用Data Annotation Validator Attributes
  System.ComponentModel.DataAnnotations命名空间下包括四个属性：
• Range:范围验证
• ReqularExpression：正则表达式验证
• Required：必须验证
• StringLength：字符串长度验证
• Validation：这是所有验证属性的基类。

使用Data Annotation Validators
using  System.ComponentModel;
using  System.ComponentModel.DataAnnotations;

namespace  MvcApplication4.Models
{
     public   class  Test
    {
         public   int  Id {  get ;  set ; }

        [Required]
        [StringLength( 10 )]
         public   string  Name {  get ;  set ; }

        [Required]
         public   string  Description {  get ;  set ; }

        [DisplayName( " Price " )]
        [Required]
        [RegularExpression( @" ^/$?/d+(/.(/d{2}))?$ " )]
         public   decimal  UnitPrice {  get ;  set ; }

    }
}