C# 中的嵌套中继器

Question

您好，我必须在转发器中显示分层信息（有四个级别）。为此，我决定使用嵌套中继器控件。 我在 MSDN 上找到了这篇文章，http://support.microsoft.com/kb/306154，它展示了如何使用嵌套中继器获取两个级别的信息。 有人可以帮我将其扩展到四个级别吗？ 一个示例代码将非常有用。谢谢你。

Answer 1

HTML 代码：

<asp:Repeater ID="Repeater1" runat="server" 
        onitemdatabound="Repeater1_ItemDataBound">
        <ItemTemplate>
            <h1>
                Repeater 1</h1>
            <asp:Repeater ID="Repeater2" runat="server" onitemdatabound="Repeater2_ItemDataBound">
                <ItemTemplate>
                    <h1>
                        Repeater 2
                    </h1>
                    <asp:Repeater ID="Repeater3" runat="server" onitemdatabound="Repeater3_ItemDataBound">
                        <ItemTemplate>
                            <h1>
                                Repeater 3
                            </h1>
                            <asp:Repeater ID="Repeater4" runat="server" onitemdatabound="Repeater4_ItemDataBound">
                                <ItemTemplate>
                                    <h1>
                                        Repeater 4
                                    </h1>
                                </ItemTemplate>
                            </asp:Repeater>
                        </ItemTemplate>
                    </asp:Repeater>
                </ItemTemplate>
            </asp:Repeater>
        </ItemTemplate>
    </asp:Repeater>

C#代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        DataTable dt1 = new DataTable();
        //Need to assign the Data in datatable
        Repeater1.DataSource = dt1;
        Repeater1.DataBind();

    }
    protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
        {
            Repeater Repeater2 = (Repeater)(e.Item.FindControl("Repeater2"));

            DataTable dt2 = new DataTable();
            //Need to assign the Data in datatable
            Repeater2.DataSource = dt2;
            Repeater2.DataBind();
        }

    }
    protected void Repeater2_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
        {
            Repeater Repeater3 = (Repeater)(e.Item.FindControl("Repeater3"));

            DataTable dt3 = new DataTable();
            //Need to assign the Data in datatable
            Repeater3.DataSource = dt3;
            Repeater3.DataBind();
        }

    }

    protected void Repeater3_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
        {
            Repeater Repeater4 = (Repeater)(e.Item.FindControl("Repeater4"));

            DataTable dt4 = new DataTable();
            //Need to assign the Data in datatable
            Repeater4.DataSource = dt4;
            Repeater4.DataBind();
        }

    }
}

Answer 2

互联网上有很多可用的示例。以下是其中的一些。

http://www.codeproject.com/Tips/563919/Nested-Repeater-Controls-in-ASP-NET

http://support.microsoft.com/kb/326338

您也可以从下面的链接下载代码。 http://everymanprogrammer.com/index.php/nested-repeaters-do-it-clean-and-simple-a-beginners-tutorial-part-2/

Answer 3

在第一个答案的基础上，您可以在 Page_Load 上传入表数据，而不是在 ItemDataBound 函数中构建表，将其设置为 ViewState 变量，然后在绑定时检索它：

private DataTable GetCachedDataTable(string strTable)
{
    DataTable dtableCached = (DataTable)this.ViewState[strTableCache];
    return dtableCached;
}
protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        this.ViewState["TblTwo_Cache"] = null;
        DataTable tblOne = new DataTable();
        DataTable tblTwo = new DataTable();
        myFunctionReturningTwoTables(ref tblOne, ref tblTwo);

        // Bind the first one
        if (tblOne != null)
        {
            // This first line assumes an <asp:Panel ID=pnlMain runat=server> 
            // tag is added in front of the Repeater1 tag in the ASPX markup, above,
            // and an </asp:Panel> tag is after the last </asp:Repeater> tag
            Repeater rptr = pnlMain.FindControl("Repeater1") as Repeater;
            rptr.ItemDataBound += new RepeaterItemEventHandler(rptrItemDataBound);
            rptr.DataSource = tblOne;
            rptr.DataBind();
        }
        // Cache the 2nd (and others...) like this
        if (tblTwo != null)
        {
            this.ViewState["TblTwo_Cache"] = tblTwo;
        }
    }
}
protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        Repeater rptr2 = e.Item.FindControl("Repeater2") as Repeater;
        if (rptr2 != null)
        {
            DataTable dt = new DataTable();
            // Now, pull it out of cache
            dt = GetCachedDataTable("TblTwo_Cache");
            if (dt != null)
            {
                rptr2.DataSource = dt;
                rptr2.DataBind();
            }
        }
    }
}

Answer 4

如果您有强类型数据类型，最好使用<asp:Repeater> 控件中提供的ItemTypeproperty，以便您可以轻松地将嵌套<asp:Repeater> 控件的DataSource 属性设置为<%#Container.DataItem %>，如下所示每个嵌套中继器的步骤相同。

代码示例：

<asp:Repeater ID="associatedDataRepeater" runat="server">
  <ItemTemplate>

    <asp:Repeater runat="server" DataSource='<%#Container.DataItem %>'>
      <ItemTemplate>

      </ItemTemplate>
    </asp:Repeater>

  </ItemTemplate>
</asp:Repeater>