轉發器數據綁定中的轉發器（無回發）

Question

對於該解決方案，我不能使用任何回發方法，因為這都是通過ajax進行的。 該解決方案需要在asp.net代碼中實現。

我有一個List<WebPage> ，其中包含鏈接(List<Link>)並且我需要所有鏈接來綁定重復信息，例如頁面標題，ID，URL。 這是我目前的中繼器。

<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>

當然這不起作用，我該怎么辦？

謝謝你的幫助！

Answer 1

我假設您要在此處解決的問題是如何在嵌套對象中包含多個級別的屬性-某些屬性來自頂層，而其他屬性則來自底層。 一種簡單的方法是將內部集合轉換為包含您需要的所有屬性的混合類型的新類型。

這是一個代碼示例，說明了使用IEnumerable.Select和C＃匿名類創建新類的技術：

<%@ 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>