Asp.net MVC 3实例学习之ExtShop（四）――完成产品列表页

在完成产品列表页前要做一些准备功夫。首先是去下载MvcPager用了为产品列表分页。下载的可能是基于MVC 2的，没关系，可以用在MVC 3上。如果有担心，下载源代码重新编译一次好了。下载后将DLL添加到引用里。

接着是要修改一下路由以实现“Catalog/List/[id]/[page]”的访问。打开“Global.asax.cs”文件，然后在默认路由之前添加以下代码：

routes . MapRoute (
" Catalog " , // Route name
" Catalog/List/{id}/{page} " , // URL with parameters
new { controller = " Catalog " , action = " List " , page = 1 } // Parameter defaults
) ;

现在打开CatalogController.cs文件，在文件头添加对MvcPager的引用，代码如下：

using Webdiyer . WebControls . Mvc;

然后修改Index操作的代码如下：

public ActionResult Index ( int? id )
{
PagedList < T_Products > q = dc . T_Products . OrderByDescending ( m = > m . CreateTime ) . ToPagedList ( id ?? 1 , 8 ) ;
return View ( q ) ;
}

代码传入的id是页码而不是产品分类编码，这个要注意。因为要使用分页，所以传递给视图的是PagedList对象，而不是Queryable，这也是要注意的地方。因而，查询结果需要通过toPagedList方法将Queryable对象转换为PagedList对象。第1个参数是当前页面，如果id为空，则默认为第1页。第2个参数是每页显示的产品数量，在这里是8个。

在“Index”上单击鼠标右键，选择“添加视图”（ ，今天换了中文版，菜单也变了）。在视图中添加以下代码：

@ using Webdiyer . WebControls . Mvc ;
@ model PagedList < Extshop . Models . T_Products >

@ {
ViewBag . Title = " 产品列表 " ;
PageData [ " id " ] = " " ;
}
< div class = " nav " >
< a href = " @Url.Action( " " , " Catalog " ) " > 产品 < / a >
< / div > < br / >
< div id = " contentMain " style = " width:760px; " >
< span class = " header " style = " width:750px; " > 产品列表 < / span >
@ {
foreach ( var c in Model )
{
< ul >
< li > < a href = ' @ Url . Action ( " Details " , " Product " , new { id = c . ProductID } ) ' > < img src = ' / Images / products / @ c . SamllImageUrl ' alt = " @c.Title " / > < / a > < / li >
< li class = ' title ' > < a href = ' @ Url . Action ( " Details " , " Product " , new { id = c . ProductID } ) ' > @ c . Title < / a > < / li >
< li > 市场价： < del > @ c . MarketPrice . ToString ( " C " ) < / del > < / li >
< li > 当前价： @ c . UnitPrice . ToString ( " C " ) < / li >
< li > < span class = " rating-title " > 评 价： < / span >
< div class = ' rating ' id = " @c.ProductID.ToString( " rat - 0 " ) " >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 1 " @ ( c . TotalRating = = 1 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 2 " @ ( c . TotalRating = = 2 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 3 " @ ( c . TotalRating = = 3 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 4 " @ ( c . TotalRating = = 4 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 5 " @ ( c . TotalRating = = 5 ? " checked='checked' " : " " ) / >
< / div >
< / li >
< / ul >
}
}
< div class = " clear " > < / div >
< div class = ' pagenav ' > @ Html . Pager ( Model , new PagerOptions { PageIndexParameterName = " id " } ) < / div >
< / div >

< script type = " text/javascript " >
jQuery ( function ( ) {
$ ( " div .rating " ) . stars ( ) ;
} ) ;
< / script >

代码第一句引用MvcPager，第二句定义接收的数据模型类型。因为是所以产品列表，所以PageData["id"]设置为空字符串。其余代码和首页的差不多。第34句使用HTML方式显示分页代码。这里要注意的是PagerOptions选项中的PageIndexParameterName要设置为id，因为操作中接收的当前页参数是以id定义的。

页面需要正常显示，还需要在Site.css中添加以下代码：

1   #contentMain .clear { clear : both ; }
2   #contentMain .pagenav { width : 760px ; text-align : center ; margin-bottom : 10px ; }
切换回CatalogController.cs文件，在Index操作下添加一个List操作，其代码如下：
1   public ActionResult List(string id, int? page)
2   {
3   ViewData["id"] = id;
4   PagedList q = dc.T_Products
5   .Where(m => dc.T_Categories.Where(n => n.CategoryID.Substring(0, id.Length) == id).Select(n => n.CategoryID ).Contains(m.CategoryID))
6   .OrderByDescending(m => m.CreateTime).ToPagedList(page ?? 1, 4);
7   return View(q);
8   }

从代码可以看到，List操作有两个参数，第1个是分类id，第2个是当前页号。第3行通过ViewData["id"]向视图传递当前的分类id，以更新左边分类列表以及显示导航条。其余的和Index操作差不多。现在为List操作创建一个视图，视图内代码如下：

@ using Webdiyer . WebControls . Mvc ;
@ model PagedList < Extshop . Models . T_Products >
@ {
ViewBag . Title = " 产品列表 " ;
PageData [ " id " ] = ViewData [ " id " ] ;
}

< div class = " nav " >
< a href = " @Url.Action( " " , " Catalog " ) " > 产品 < / a >
@ { Html . RenderAction ( " Navbar " , " Catalog " , new { id = ViewData [ " id " ] } ) ; }
< / div > < br / >
< div id = " contentMain " style = " width:760px; " >
< span class = " header " style = " width:750px; " > 产品列表 < / span >
@ {
foreach ( var c in Model )
{
< ul >
< li > < a href = ' @ Url . Action ( " Details " , " Product " , new { id = c . ProductID } ) ' > < img src = ' / Images / products / @ c . SamllImageUrl ' alt = " @c.Title " / > < / a > < / li >
< li class = ' title ' > < a href = ' @ Url . Action ( " Details " , " Product " , new { id = c . ProductID } ) ' > @ c . Title < / a > < / li >
< li > 市场价： < del > @ c . MarketPrice . ToString ( " C " ) < / del > < / li >
< li > 当前价： @ c . UnitPrice . ToString ( " C " ) < / li >
< li > < span class = " rating-title " > 评 价： < / span >
< div class = ' rating ' id = " @c.ProductID.ToString( " rat - 0 " ) " >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 1 " @ ( c . TotalRating = = 1 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 2 " @ ( c . TotalRating = = 2 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 3 " @ ( c . TotalRating = = 3 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 4 " @ ( c . TotalRating = = 4 ? " checked='checked' " : " " ) / >
< input name = " @c.ProductID.ToString( " Star0 " ) " type = " radio " class = " star " disabled = " disabled " value = " 5 " @ ( c . TotalRating = = 5 ? " checked='checked' " : " " ) / >
< / div >
< / li >
< / ul >
}
}
< div class = " clear " > < / div >
< div class = ' pagenav ' > @ Html . Pager ( Model , new PagerOptions { PageIndexParameterName = " page " } ) < / div >
< / div >

< script type = " text/javascript " >
jQuery ( function ( ) {
$ ( " div .rating " ) . stars ( ) ;
} ) ;
< / script >

代码第10行通过一个分部视图显示导航菜单。第35行要注意PageIndexParameterName是“page”，而不是Index视图的“id”了。

下一步要做的是完成导航条的显示。将文件切换回CatalogController.cs文件，添加一个名称为“Navbar”的子操作，其代码如下：

[ ChildActionOnly ]
public ActionResult Navbar ( string id )
{
List < string > idlist = new List < string > ( ) ;
idlist . Add ( id ) ;
for ( int i = 0 ; i < ( id . Length - 2 ) ; i = i + 3 )
{
idlist . Add ( id . Substring ( 0 , i + 3 ) ) ;
}
var q = dc . T_Categories . Where ( m = > idlist . Contains ( m . CategoryID ) ) . OrderBy ( m = > m . CategoryID ) ;
return PartialView ( q ) ;
}

代码首先获取了当前分类的父类编号，然后从数据库一次查询出所有类别并排序。现在为该子操作创建一个分部视图，视图代码如下：

@ model IEnumerable < Extshop . Models . T_Categories >

@ {
foreach ( var c in Model )
{
@ Html . Raw ( " >> " ) < a href = ' @ Url . Action ( " List " , " Catalog " , new { id = c . CategoryID } ) ' > @ c . Titel < / a >
}
}

代码中，“>>”的显示必须用Html的Raw方法显示，不然会提示错误，使用“>”也不行，估计是和Razor的语法有冲突。是否有其它办法，没去研究了。

至此，产品列表页的就已经完成了。
BTW：因为项目还没完成，所以没考虑提供源代码，但有读者希望在看文章的同时能提供源代码做参考，所以从本文开始，每完成一节，就提供到该节的代码。
源代码：http://download.csdn.net/source/2996287