周末加班，闲来无事，写篇博客，讲讲怎么在 ASP.NET MVC2中使用用户控件。首先我们新建一个用户控件，

我们命名为SelectGroup.ascx，代码如下

1. <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> 
2. <script language="javascript" type="text/javascript" src="<%=Url.Content("~/Areas/Util/Scripts/SelectGroup.js") %>"></script> 
3. <div> 
4.     <table> 
5.         <tr> 
6.             <td style="text-align:right"> 
7.                 招生批次  
8.             </td> 
9.             <td> 
10.                 <select id="admissionBatch" style="width: 150px"> 
11.                 </select> 
12.             </td> 
13.             <td style="text-align:right; width:80px"> 
14.                 学历层次  
15.             </td> 
16.             <td> 
17.                 <select id="edcuationLevel" style="width: 150px"> 
18.                 </select> 
19.             </td> 
20.             <td style="text-align:right; width:80px"> 
21.                 专业名称  
22.             </td> 
23.             <td> 
24.                 <select id="professional" style="width: 150px"> 
25.                 </select> 
26.             </td> 
27.         </tr> 
28.     </table> 
29. </div> 

我们再编写其对应的控制器如下

1. using System;  
2. using System.Collections.Generic;  
3. using System.Linq;  
4. using System.Web;  
5. using System.Web.Mvc;  
6.  
7. namespace EducationManage.Areas.Util.Controllers  
8. {  
9.     using Utility.Json;  
10.     using EducationManage.Areas.Util.Models;  
11.     public class SelectGroupController : Controller  
12.     {  
13.         //  
14.         // GET: /Util/SelectGroup/  
15.         SelectgroupEntities selectgroupEntities = new SelectgroupEntities();  
16.  
17.         /// <summary>  
18.         /// 招生批次  
19.         /// 李磊 2010-10-29  
20.         /// </summary>  
21.         /// <returns></returns>  
22.         public JsonResult GetAdmissionBatch()  
23.         {  
24.             List<SG_Admission_Batchs> admissionBatchsList = selectgroupEntities.admission_batchs.ToList();  
25.             return Json(admissionBatchsList, JsonRequestBehavior.AllowGet);  
26.         }  
27.  
28.         /// <summary>  
29.         /// 学历层次  
30.         /// 李磊 2010-10-29  
31.         /// </summary>  
32.         /// <returns></returns>  
33.         public JsonResult GetEducationLevel()  
34.         {  
35.             List<SG_Education_Levels> educationLevelList = selectgroupEntities.education_levels.ToList();  
36.             return Json(educationLevelList, JsonRequestBehavior.AllowGet);  
37.         }  
38.  
39.         /// <summary>  
40.         /// 专业  
41.         /// 李磊 2010-10-29  
42.         /// </summary>  
43.         /// <returns></returns>  
44.         public JsonResult GetProfessional()  
45.         {  
46.             List<SG_Professional> professionalList = selectgroupEntities.professional.ToList();  
47.             return Json(professionalList, JsonRequestBehavior.AllowGet);  
48.         }  
49.  
50.         /// <summary>  
51.         /// 学籍批次  
52.         /// 李磊 2010-10-29  
53.         /// </summary>  
54.         /// <returns></returns>  
55.         public JsonResult GetRollBatch()  
56.         {  
57.             List<SG_Roll_Batchs> rollBatchList = selectgroupEntities.roll_batchs.ToList();  
58.             return Json(rollBatchList, JsonRequestBehavior.AllowGet);  
59.         }  
60.  
61.         /// <summary>  
62.         /// 专业学历层次联动  
63.         /// 李磊 2010-10-29  
64.         /// </summary>  
65.         /// <param name="id"></param>  
66.         /// <returns></returns>  
67.         public JsonResult GetProfessionalByEducationLevel(string id)  
68.         {  
69.             try 
70.             {  
71.                 List<string> professionalIdList = selectgroupEntities.professional_educationlevel.Where(pe => pe.education_id == id).Select(pe => pe.prefessional_code).ToList();  
72.                 List<SG_Professional> professionalList = selectgroupEntities.professional.Where(p => professionalIdList.Contains(p.prefessional_code)).ToList();  
73.                 return Json(professionalList, JsonRequestBehavior.AllowGet);  
74.             }  
75.             catch 
76.             {  
77.                 return null;  
78.             }  
79.         }  
80.     }  
81. }  

好的，我们接着编写js.

 首先在js的顶层引入 ///<reference path = "../../../Scripts/jQuery-1.4.1.js"/>这样编写js代码就有智能提示，如下

1. $(document).ready(function () {  
2.       
3.     $.ajaxSetup({  
4.         cache: false 
5.     });  
6.     $.getJSON("/SelectGroup/GetAdmissionBatch/", function (data) {  
7.         $("#admissionBatch").append("<option value=''>请选择</option>");  
8.         $.each(data, function (i, item) {  
9.             $("<option></option>")  
10.             .val(item["admission_batch_id"])  
11.             .text(item["name"])  
12.             .appendTo($("#admissionBatch"));  
13.         });  
14.  
15.     });  
16.  
17.     $.getJSON("/SelectGroup/GetEducationLevel/", function (data) {  
18.         $("#edcuationLevel").append("<option value=''>请选择</option>");  
19.         $.each(data, function (i, item) {  
20.             $("<option></option>")  
21.             .val(item["education_id"])  
22.             .text(item["name"])  
23.             .appendTo($("#edcuationLevel"));  
24.         });  
25.  
26.     });  
27.  
28.     $.getJSON("/SelectGroup/GetProfessional/", function (data) {  
29.         $("#professional").append("<option value=''>请选择</option>");  
30.         $.each(data, function (i, item) {  
31.             $("<option></option>")  
32.             .val(item["prefessional_code"])  
33.             .text(item["name"])  
34.             .appendTo($("#professional"));  
35.         });  
36.  
37.     });  
38.  
39.     $("#edcuationLevel").change(function () {  
40.         $("#professional").empty();  
41.         $("#professional").append("<option value='0'>请选择</option>");  
42.         $.getJSON("/SelectGroup/GetProfessionalByEducationLevel/" + $("#edcuationLevel").val(), function (data) {  
43.             $.each(data, function (i, item) {  
44.                 $("<option></option>")  
45.             .val(item["prefessional_code"])  
46.             .text(item["name"])  
47.             .appendTo($("#professional"));  
48.             });  
49.  
50.         });  
51.     });  
52.  
53. }) 

ok，好了，我们看看在页面怎么引用

1. <%Html.RenderPartial("~/Areas/Util/Views/Shared/SelectGroup.ascx"); %> 

只要你将这段代码放在页面上即可。Html.RenderPartial有很多重载，你也可以给用户控件传递一个需要绑定的对象。说到这里谈谈Html.RenderPartial和Html.Partial的区别。Html.RenderPartial是直接输出至当前HttpContext，而Html.Partial是将视图内容直接生成一个字符串并返回。所以在引用的时候不一样分别为<% Html.RenderPartial("~/Areas/Util/Views/Shared/SelectGroup.ascx"); %>和<%= Html.Partial("~/Areas/Util/Views/Shared/SelectGroup.ascx"); %>。说到这两个不免要说Html.RenderAction，它是通过Controller中的Action来调用用户控件。上面的代码大家可以根据js和控制器代码看到，每个下拉列表的绑定都有自己的控制器返回数据，在页面加载完成的时候去调用自己的控制器获取下拉列表数据。如果我们用Html.RenderAction就没有那么麻烦了，看看控制器代码

1. using System;  
2. using System.Collections.Generic;  
3. using System.Linq;  
4. using System.Web;  
5. using System.Web.Mvc;  
6.  
7. namespace EducationManage.Areas.Util.Controllers  
8. {  
9.     using Utility.Json;  
10.     using EducationManage.Areas.Util.Models;  
11.     public class SectionGroupController : Controller  
12.     {  
13.         //  
14.         // GET: /Util/SectionGroup/  
15.         SelectgroupEntities selectgroupEntities = new SelectgroupEntities();  
16.         public ActionResult Index()  
17.         {  
18.             List<SG_Admission_Batchs> admissionBatchList = selectgroupEntities.admission_batchs.ToList();  
19.             SelectList admissionBatch = new SelectList(admissionBatchList, "admission_batch_id", "name", "");  
20.             ViewData.Add("admissionBatch", admissionBatch);  
21.  
22.             List<SG_Education_Levels> educationLevelList = selectgroupEntities.education_levels.ToList();  
23.             SelectList educationLevel = new SelectList(educationLevelList, "education_id", "name", "");  
24.             ViewData.Add("educationLevel", educationLevel);  
25.  
26.             List<SG_Professional> professionalList = selectgroupEntities.professional.ToList();  
27.             SelectList professional = new SelectList(professionalList, "prefessional_code", "name", "");  
28.             ViewData.Add("professional", professional);  
29.             return PartialView("~/Areas/Util/Views/Shared/SectionGroup.ascx");  
30.         }  
31.  
32.     }  
33. }  

再看看前台

1. <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> 
2. <script language="javascript" type="text/javascript" src="<%=Url.Content("~/Areas/Util/Scripts/SelectGroup.js") %>" /> 
3. <div> 
4.     <table> 
5.         <tr> 
6.             <td style="text-align: right"> 
7.                 招生批次 
8.             </td> 
9.             <td> 
10.                 <%:Html.DropDownList("admissionBatch", ViewData["admissionBatch"] as SelectList, "请选择", new { id = "admissionBatch", style = "width: 150px" })%> 
11.             </td> 
12.             <td style="text-align: right; width: 80px"> 
13.                 学历层次 
14.             </td> 
15.             <td> 
16.                 <%:Html.DropDownList("edcuationLevel", ViewData["educationLevel"] as SelectList, "请选择", new { id = "edcuationLevel", style = "width: 150px" })%> 
17.             </td> 
18.             <td style="text-align: right; width: 80px"> 
19.                 专业名称 
20.             </td> 
21.             <td> 
22.                 <%:Html.DropDownList("professional", ViewData["professional"] as SelectList, "请选择", new { id = "professional", style = "width: 150px" })%> 
23.             </td> 
24.         </tr> 
25.     </table> 
26. </div> 

在这里我们一次性就获取到了所有下拉列表要绑定的数据。我们只需要在前台这样应用即可<%Html.RenderAction("Index", "SectionGroup");%>。好了，在MVC2中使用用户控件就是这么简单。

本文转自 BruceAndLee 51CTO博客，原文链接：http://blog.51cto.com/leelei/412702，如需转载请自行联系原作者