使用asp.net生成類別和子類別列表mvc2

Question

我有一種感覺，我正在做這個可怕的，可怕的錯誤。嵌套循環？列出子類別的最佳做法是什麼？我有一種感覺，它涉及在我的控制器動作中準備列表，並通過一些動作結果發送給客戶端，但我不知道從哪裏開始？任何人都能指出我正確的方向？這裏是我的哈克代碼：

<h2>Categories</h2> 
    <a href="javascript:;" onclick="newCategory()">Create New Category</a> 
<br /> 
    <ul class="parent"> 
     <%foreach (var category in Model.Categories){%> 
      <%-- List all of the top-level parent categories --%> 
      <%if (category.IsParent && category.ParentId == 0)%> 
      <li> 
       <span class="buttons"><a href="javascript:;" onclick="editCategory(<%:category.CategoryId%>)" class="edit"></a> <a href="javascript:;" onclick="deleteCategory(<%:category.CategoryId%>)" class="delete"></a></span> 
       <span class="categoryName"><%:category.CategoryName%></span> 
       <span class="positionButtons"><%:Html.ActionLink(" ", "MoveCategoryUp", new {id = category.CategoryId}, 
               new {Class = "moveUp"})%><%:Html.ActionLink(" ", "MoveCategoryDown", new {id = category.CategoryId}, 
               new {Class = "moveDown"})%></span> 
       <%-- List all of the subs for each parent --%> 

        <ul> 
<%-- Level 1 --%>  <%foreach (var sub1 in Model.Categories){%> 
          <%if (sub1.ParentId == category.CategoryId){%> 
           <li> 
            <span class="buttons"><a href="javascript:;" onclick="editCategory(<%:sub1.CategoryId%>)" class="edit"></a> <a href="javascript:;" onclick="deleteCategory(<%:sub1.CategoryId%>)" class="delete"></a></span> 
            <span class="categoryName"><%:category.CategoryName%></span> 
            <span class="positionButtons"><%:Html.ActionLink(" ", "MoveCategoryUp", new {id = sub1.CategoryId},new {Class = "moveUp"})%><%:Html.ActionLink(" ", "MoveCategoryDown", new {id = sub1.CategoryId},new {Class = "moveDown"})%></span> 

            <%-- List all of the subs for each parent --%> 
            <%if (sub1.IsParent){%> 
            <ul> 
<%-- Level 2 --%>      <%foreach (var sub2 in Model.Categories){%> 
              <%if (sub2.ParentId == sub1.CategoryId){%> 
               <li> 
                <span class="buttons"><a href="javascript:;" onclick="editCategory(<%:sub2.CategoryId%>)" class="edit"></a> <a href="javascript:;" onclick="deleteCategory(<%:sub2.CategoryId%>)" class="delete"></a></span> 
                <span class="categoryName"><%:category.CategoryName%></span> 
                <span class="positionButtons"><%:Html.ActionLink(" ", "MoveCategoryUp", new {id = sub2.CategoryId},new {Class = "moveUp"})%><%:Html.ActionLink(" ", "MoveCategoryDown", new {id = sub2.CategoryId},new {Class = "moveDown"})%></span> 
                <%-- List all of the subs for each parent --%> 
                <%if (sub2.IsParent){%> 
                <ul> 
<%-- Level 3 --%>          <%foreach (var sub3 in Model.Categories){%> 
                  <%if (sub3.ParentId == sub2.CategoryId){%> 
                   <li> 
                    <span class="buttons"><a href="javascript:;" onclick="editCategory(<%:sub3.CategoryId%>)" class="edit"></a> <a href="javascript:;" onclick="deleteCategory(<%:sub3.CategoryId%>)" class="delete"></a></span> 
                    <span class="categoryName"><%:category.CategoryName%></span> 
                    <span class="positionButtons"><%:Html.ActionLink(" ", "MoveCategoryUp",new {id = sub3.CategoryId},new {Class = "moveUp"})%><%:Html.ActionLink(" ", "MoveCategoryDown",new {id = sub3.CategoryId},new {Class = "moveDown"})%></span> 

                    <%-- List all of the subs for each parent --%> 
                    <%if (sub3.IsParent){%> 
                    <ul> 
<%-- Level 4 --%>              <%foreach (var sub4 in Model.Categories){%> 
                      <%if (sub4.ParentId == sub3.CategoryId){%> 
                       <li> 
                        <span class="buttons"><a href="javascript:;" onclick="editCategory(<%:sub4.CategoryId%>)" class="edit"></a> <a href="javascript:;" onclick="deleteCategory(<%:sub4.CategoryId%>)" class="delete"></a></span> 
                        <span class="categoryName"><%:category.CategoryName%></span> 
                        <span class="positionButtons"><%:Html.ActionLink(" ", "MoveCategoryUp", new {id = sub4.CategoryId}, new {Class = "moveUp"})%><%:Html.ActionLink(" ", "MoveCategoryDown", new {id = sub4.CategoryId}, new {Class = "moveDown"})%></span> 

                        <%-- If more than 4 levels of subcategories are required, put another level here --%> 
                       </li> 
                      <%}%> 
                     <%}%> 
                    </ul> 
                    <%}%> 
                   </li> 
                  <%}%> 
                 <%}%> 
                </ul> 
                <%}%> 
               </li> 
              <%}%> 
             <%}%> 
            </ul> 
            <%}%> 
           </li> 
          <%}%> 
         <%}%> 
        </ul> 
      </li> 

     <%}%> 

    </ul> 

編輯

不幸的是這個代碼不渲染我在尋找的結果，所以我不能真正提供遠不止此：http://jsfiddle.net/EeaGr/每個項目都有按鈕用於其類別的編輯/刪除和上移/移動選項。我的類別具有以下屬性：

類別ID：整數

名稱：字符串

PARENTID：整數

IsParent：布爾

位置：整數

Answer 1

首先，我會更改類別的結構，以便每個Category具有Subcategories屬性。

然後，你應該創建一個用戶控件呈現一個Category，如果該類別包含子類別，它遞歸調用自身：

CategoryControl.ascx：

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Category>" %> 
<%@ Import Namespace="so_subcats.Model" %> 
<li><%= Model.Name %> 
    <% if (Model.Subcategories != null) { %> 
     <ul> 
     <% foreach (Category subcat in Model.Subcategories) 
      Html.RenderPartial("CategoryControl", subcat); %> 
     </ul> 
    <% } %> 
</li> 

然後，只需創建一個視圖該控制器針對每個頂級類別呈現該控件：

Categories.aspx：

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" 
    Inherits="System.Web.Mvc.ViewPage<IEnumerable<Category>>" %> 
<%@ Import Namespace="so_subcats.Model" %> 

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

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

    <h2>Categories</h2> 
     <ul> 
     <% foreach (Category cat in Model) 
      Html.RenderPartial("CategoryControl", cat); %> 
     </ul> 

</asp:Content> 

當然，如果你不想改變你的類的結構，你也可以使用這個解決方案，你只需要稍微修改它。