基於.NET中:自動將請求參數綁定到ASPX、ASHX和MVC的方法(菜鳥必看)

前言

剛開始做AJAX應用的時候，經常要手工解析客戶端傳遞的參數，這個過程極其無聊，而且代碼中充斥著：Request["xxx"]之類的代碼。

這篇文章的目的就是告訴初學者如何自動將客戶端用AJAX發送的參數自動綁定為強類型的成員屬性或方法參數。

自動綁定到ASPX和ASHX

框架支持
復制代碼 代碼如下:
using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 namespace Happy.Web
 {
     public interface IWantAutoBindProperty
     {
     }
 }

復制代碼 代碼如下:
using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 namespace Happy.Web
 {
     [AttributeUsage(AttributeTargets.Property, AllowMultiple = true)]
     public sealed class AutoBind : Attribute
     {
     }
 }

復制代碼 代碼如下:
using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 using System.Web;

 using Newtonsoft.Json;

 using Happy.ExtensionMethods.Reflection;

 namespace Happy.Web
 {
     public class JsonBinderModule : IHttpModule
     {
         public void Init(HttpApplication context)
         {
             context.PreRequestHandlerExecute += OnPreRequestHandlerExecute;
         }

         private void OnPreRequestHandlerExecute(object sender, EventArgs e)
         {
             if (!(HttpContext.Current.CurrentHandler is IWantAutoBindProperty))
             {
                 return;
             }

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

             foreach (var property in properties)
             {
                 if (!property.IsDefined(typeof(AutoBind), true))
                 {
                     continue;
                 }

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

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

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

         public void Dispose()
         {
         }
     }
 }

代碼示例
復制代碼 代碼如下:
<?xml version="1.0" encoding="utf-8"?>

 <configuration>

     <system.web>
       <compilation debug="false" targetFramework="4.0" />
       <httpModules>
         <add name="JsonBinderModule" type="Happy.Web.JsonBinderModule"/>
       </httpModules>
     </system.web>

 </configuration>

復制代碼 代碼如下:
/// <reference path="../ext-all-debug-w-comments.js" />
 var data = {
     Name: '段光偉',
     Age: 28
 };

 Ext.Ajax.request({
     url: '../handlers/JsonBinderTest.ashx',
     method: 'POST',
     params: { user: Ext.encode(data) }
 });

復制代碼 代碼如下:
<%@ WebHandler Language="C#" Class="JsonBinderTest" %>

 using System;
 using System.Web;

 using Happy.Web;

 public class JsonBinderTest : IHttpHandler, IWantAutoBindProperty
 {
     [AutoBind]
     public User user { get; set; }

     public void ProcessRequest(HttpContext context)
     {
         context.Response.ContentType = "text/plain";
         context.Response.Write(string.Format("姓名：{0}，年齡：{1}", user.Name, user.Age));
     }

     public bool IsReusable
     {
         get
         {
             return false;
         }
     }
 }

 public class User
 {
     public string Name { get; set; }

     public int Age { get; set; }
 }

運行結果

自動綁定到MVC
框架支持
復制代碼 代碼如下:
using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 using System.Web.Mvc;

 using Newtonsoft.Json;

 namespace Tenoner.Web.Mvc
 {
     public class JsonBinder : IModelBinder
     {
         public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
         {
             string json = controllerContext.HttpContext.Request[bindingContext.ModelName];

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