中继器数据绑定中的中继器（无回发）

Question

对于解决方案，我不能使用任何回发方法，因为这都是通过ajax完成的。该解决方案需要在asp.net代码中实现。

我有一个 List ，其中包含链接列表(List)，我需要所有链接来绑定重复信息，例如页面标题、id ，网址。这是我现在的中继器。

<div id="result">
    <asp:Repeater runat="server" id="results">
        <Itemtemplate>
            <asp:Repeater runat="server" datasource='<%# Eval("Links") %>'>
                <Itemtemplate>
                    <tr class="gradeX odd">
                        <td><%# Eval("Id") %></td> //property of WebPage (part of results repeater)
                        <td><%# Eval("Title") %></td> //property of WebPage (part of results repeater)
                        <td><%# Eval("Url") %></td> //property of WebPage (part of results repeater)
                        <td><%# Eval("URL") %></td>//Property of Link
                        <td><%# Eval("URLType") %></td> //Property of Link
                        <td><%# Eval("URLState") %></td> //Property of Link
                    </tr>
                </Itemtemplate>
                </asp:Repeater>
        </Itemtemplate>
    </asp:Repeater>
</div>

当然这不起作用，我该怎么做呢？

感谢您的帮助！

Answer 1

我假设您在这里试图解决的问题是如何在嵌套对象中包含多个级别的属性 - 一些属性来自顶层，但其他属性来自较低级别。实现此目的的一种简单方法是将内部集合转换为新类型，其中包含您需要的所有属性的组合。

下面的代码示例使用 IEnumerable.Select 演示了此技术 和 C# 匿名类来创建一个新类：

<%@ Page Title="Home Page" Language="C#" %>
<div id="result"> 
    <asp:Repeater runat="server" id="results"> 
        <ItemTemplate> 
            <asp:Repeater runat="server" datasource='<%# ((WebPage)Container.DataItem).Links.Select ( link => new {
                                Id = ((WebPage)Container.DataItem).Id, 
                                Title = ((WebPage)Container.DataItem).Title, 
                                Url = ((WebPage)Container.DataItem).Url, 
                                URL = link.URL,
                                URLType = link.URLType,
                                URLState = link.URLState
                                }) %>'> 
                <ItemTemplate> 
                    <tr class="gradeX odd"> 
                        <td><%# Eval("Id") %></td> <!--property of WebPage (part of results repeater) -->
                        <td><%# Eval("Title") %></td> <!--property of WebPage (part of results repeater) -->
                        <td><%# Eval("Url") %></td> <!--property of WebPage (part of results repeater) -->
                        <td><%# Eval("URL") %></td><!--Property of Link -->
                        <td><%# Eval("URLType") %></td> <!--Property of Link--> 
                        <td><%# Eval("URLState") %></td> <!--Property of Link -->
                    </tr> 
                </ItemTemplate> 
                </asp:Repeater> 
        </Itemtemplate> 
    </asp:Repeater> 
</div> 

<script runat="server">
    public class Link
    {
        public string URL { get; set; }
        public int URLType { get; set; }
        public int URLState { get; set; }
    }
    public class WebPage
    {
        public string Id { get; set; }
        public string Title { get; set; }
        public string Url { get; set; }
        public List<Link> Links { get; set; }
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        WebPage[] pages = new WebPage[] 
        {
            new WebPage { Id = "foo", 
                Title = "foobar", 
                Url = "http://foo.bar", 
                Links = new List<Link> ( new Link[] {
                    new Link {URL = "http://something", URLType = 1, URLState = 2},
                    new Link {URL = "http://someotherthing", URLType = 3, URLState = 4}
                })
            },
            new WebPage { Id = "excellent", 
                Title = "excellent Title", 
                Url = "http://excellent.com", 
                Links = new List<Link> ( new Link[] {
                    new Link {URL = "http://excellent", URLType = 5, URLState = 6},
                    new Link {URL = "http://totallyexcellent", URLType = 7, URLState = 8}
                })
            }

        };
        results.DataSource = pages;
        results.DataBind();
    }
</script>