.NET：自动将请求参数绑定到ASPX、ASHX和MVC（菜鸟必看）

前言

刚开始做AJAX应用的时候，经常要手工解析客户端传递的参数，这个过程极其无聊，而且代码中充斥着：Request["xxx"]之类的代码。

这篇文章的目的就是告诉初学者如何自动将客户端用AJAX发送的参数自动绑定为强类型的成员属性或方法参数。

自动绑定到ASPX和ASHX

框架支持

 1 using System;

 2 using System.Collections.Generic;

 3 using System.Linq;

 4 using System.Text;

 5 using System.Threading.Tasks;

 6 

 7 namespace Happy.Web

 8 {

 9     public interface IWantAutoBindProperty

10     {

11     }

12 }

 1 using System;

 2 using System.Collections.Generic;

 3 using System.Linq;

 4 using System.Text;

 5 using System.Threading.Tasks;

 6 

 7 namespace Happy.Web

 8 {

 9     [AttributeUsage(AttributeTargets.Property, AllowMultiple = true)]

10     public sealed class AutoBind : Attribute

11     {

12     }

13 }

 1 using System;

 2 using System.Collections.Generic;

 3 using System.Linq;

 4 using System.Text;

 5 using System.Threading.Tasks;

 6 

 7 using System.Web;

 8 

 9 using Newtonsoft.Json;

10 

11 using Happy.ExtensionMethods.Reflection;

12 

13 namespace Happy.Web

14 {

15     public class JsonBinderModule : IHttpModule

16     {

17         public void Init(HttpApplication context)

18         {

19             context.PreRequestHandlerExecute += OnPreRequestHandlerExecute;

20         }

21 

22         private void OnPreRequestHandlerExecute(object sender, EventArgs e)

23         {

24             if (!(HttpContext.Current.CurrentHandler is IWantAutoBindProperty))

25             {

26                 return;

27             }

28 

29             var properties = HttpContext.Current.CurrentHandler.GetType().GetProperties();

30 

31             foreach (var property in properties)

32             {

33                 if (!property.IsDefined(typeof(AutoBind), true))

34                 {

35                     continue;

36                 }

37 

38                 string json = HttpContext.Current.Request[property.Name];

39 

40                 var value = JsonConvert.DeserializeObject(json, property.PropertyType);

41 

42                 property.SetValue(HttpContext.Current.Handler, value);

43             }

44         }

45 

46         public void Dispose()

47         {

48         }

49     }

50 }

代码示例

 1 <?xml version="1.0" encoding="utf-8"?>

 2 

 3 <configuration>

 4 

 5     <system.web>

 6       <compilation debug="false" targetFramework="4.0" />

 7       <httpModules>

 8         <add name="JsonBinderModule" type="Happy.Web.JsonBinderModule"/>

 9       </httpModules>

10     </system.web>

11 

12 </configuration>

 1 /// <reference path="../ext-all-debug-w-comments.js" />

 2 var data = {

 3     Name: '段光伟',

 4     Age: 28

 5 };

 6 

 7 Ext.Ajax.request({

 8     url: '../handlers/JsonBinderTest.ashx',

 9     method: 'POST',

10     params: { user: Ext.encode(data) }

11 });

 1 <%@ WebHandler Language="C#" Class="JsonBinderTest" %>

 2 

 3 using System;

 4 using System.Web;

 5 

 6 using Happy.Web;

 7 

 8 public class JsonBinderTest : IHttpHandler, IWantAutoBindProperty

 9 {

10     [AutoBind]

11     public User user { get; set; }

12 

13     public void ProcessRequest(HttpContext context)

14     {

15         context.Response.ContentType = "text/plain";

16         context.Response.Write(string.Format("姓名：{0}，年龄：{1}", user.Name, user.Age));

17     }

18 

19     public bool IsReusable

20     {

21         get

22         {

23             return false;

24         }

25     }

26 }

27 

28 public class User

29 {

30     public string Name { get; set; }

31 

32     public int Age { get; set; }

33 }

运行结果

自动绑定到MVC

框架支持

 1 using System;

 2 using System.Collections.Generic;

 3 using System.Linq;

 4 using System.Text;

 5 using System.Threading.Tasks;

 6 

 7 using System.Web.Mvc;

 8 

 9 using Newtonsoft.Json;

10 

11 namespace Tenoner.Web.Mvc

12 {

13     public class JsonBinder : IModelBinder

14     {

15         public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)

16         {

17             string json = controllerContext.HttpContext.Request[bindingContext.ModelName];

18 

19             return JsonConvert.DeserializeObject(json, bindingContext.ModelType);

20         }

21     }

22 }

代码示例

此处省略代码示例，有兴趣的朋友请留言交流。

备注

有些朋友应该能想到，这种模式不止能用在AJAX场景，其它场景也可以使用。