以 XML 文件为数据源进行嵌套绑定

作者：孟宪会阅读：919 发表于：2011-07-05 10:17:25

在实际的应用中，经常使用 XML 数据源进行绑定，对于单层的数据绑定比较简单，如果进行嵌套绑定，该如何实现呢？下面的方法就是在绑定事件里得到数据项，然后进行嵌套绑定的例子。XmlDataSOurce数据源的数据项类型是 System.Web.UI.WebControls.XmlDataSourceNodeDescriptor，它实现了IXPathNavigable 接口，因此可以创建 XPathNavigator 对象。例如下面的方法：

C# 代码


System.Xml.XPath.XPathNavigator nav = ((System.Xml.XPath.IXPathNavigable)e.Item.DataItem).CreateNavigator();

System.Xml.XPath.XPathNodeIterator it = nav.Select("./District");

也可以以 IEnumerable 形式的 XmlNodeList 返回，然后进行绑定：

C# 代码


IEnumerable em = XPathBinder.Select(e.Item.DataItem, "District") as IEnumerable;

em.GetEnumerator();

Repeater Repeater4 = e.Item.FindControl("Repeater4") as Repeater;

Repeater4.DataSource = em;

Repeater4.DataBind();

完整的例子代码如下：

ASPX 代码


<%@ Page Language="C#" %>



<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  protected void Page_Load(object sender, EventArgs e)

  {

    XmlDataSource xds = new XmlDataSource();

    xds.DataFile = "~/2.xml";

    xds.ID = "XmlDataSource1";

    form1.Controls.Add(xds);

    Repeater1.DataSourceID =  Repeater3.DataSourceID = "XmlDataSource1";

    Repeater1.DataBind();

    Repeater3.DataBind();

  }



  protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)

  {

    if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)

    {

      System.Xml.XPath.XPathNavigator nav = ((System.Xml.XPath.IXPathNavigable)e.Item.DataItem).CreateNavigator();

      System.Xml.XPath.XPathNodeIterator it = nav.Select("./District");

      Repeater Repeater2 = e.Item.FindControl("Repeater2") as Repeater;

      Repeater2.DataSource = it;

      Repeater2.DataBind();

    }

  }

  protected void Repeater3_ItemDataBound(object sender, RepeaterItemEventArgs e)

  {

    if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)

    {      

      IEnumerable em = XPathBinder.Select(e.Item.DataItem, "District") as IEnumerable;

      em.GetEnumerator();

      Repeater Repeater4 = e.Item.FindControl("Repeater4") as Repeater;

      Repeater4.DataSource = em;

      Repeater4.DataBind();

    }

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

</head>

<body>

  <form id="form1" runat="server">

   <h1>方法1</h1>

  <asp:Repeater ID="Repeater1" runat="server" OnItemDataBound="Repeater1_ItemDataBound">

    <ItemTemplate>

      <h2 style="background: #ede">

        <%#XPath("@text")%></h2>

      <asp:Repeater ID="Repeater2" runat="server">

      <HeaderTemplate><table border="1"></HeaderTemplate><FooterTemplate></table></FooterTemplate>

        <ItemTemplate>

          <tr><td><%#XPath("@value")%></td><td><%#XPath("@text")%></td></tr>

        </ItemTemplate>

      </asp:Repeater>

    </ItemTemplate>

  </asp:Repeater>

  <h1>方法2</h1>

  <asp:Repeater ID="Repeater3" runat="server" OnItemDataBound="Repeater3_ItemDataBound">

    <ItemTemplate>

      <h2 style="background: #ede">

        <%#XPath("@text")%></h2>

      <asp:Repeater ID="Repeater4" runat="server">

      <HeaderTemplate><table border="1"></HeaderTemplate><FooterTemplate></table></FooterTemplate>

        <ItemTemplate>

          <tr><td><%#((System.Xml.XmlNode)Container.DataItem).Attributes["value"].Value %></td><td><%#XPath("@text")%></td></tr>

        </ItemTemplate>

      </asp:Repeater>

    </ItemTemplate>

  </asp:Repeater>

  </form>

</body>

</html>

xml 文件格式如下：

XML 代码


<?xml version="1.0" encoding="utf-8"?>

<Cities>

  <City text="北京" value="bj">

    <District value="haidian" text="海淀区"></District>

    <District value="changping" text="昌平区"></District>

    <District value="chaoyang" text="朝阳区"></District>

    <District value="pinggu" text="平谷区"></District>

  </City>

  <City text="上海" value="sh">

    <District value="pudong" text="浦东区"></District>

    <District value="xuhui" text="徐汇区"></District>

  </City>

  <City text="郑州" value="zz">

    <District value="erqi" text="二七区"></District>

    <District value="huiji" text="惠济区"></District>

    <District value="jinshui" text="金水区"></District>

  </City>

</Cities>

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