没有从XML文件返回数据 [英] No data is returned from XML file
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问题描述
我正在尝试从API xml文件（URL）读取数据。链接工作并显示原始数据，但在下面的页面中使用Repeater控件时，没有显示任何属性（ns2：description）我试图访问它一个例子，所以我应该能够访问文件中的任何属性。任何人都可以建议如何更正这个？
I am trying to read data from an API xml file (URL). The link works and shows the raw data but When using the Repeater control in the page below, nothing is shown The attribute (ns2:description) I am trying to access it an example so I should be able to access any attribute in the file. Can anyone advise on how to correct this ?
<%@ Page Language="VB" ContentType="text/html" ResponseEncoding="iso-8859-1" Debug="true" %>
<%@ import Namespace="System.Data" %>
<%@ import Namespace="System" %>
<%@ import Namespace="System.IO" %>
<%@ import Namespace="System.Xml" %>
<%@ import Namespace="System.Net.HttpWebResponse" %>
<Script runat="server">
sub Page_Load
if Not Page.IsPostBack then
Dim doc as XmlDocument = new XmlDocument()
doc.Load("http://api.tradedoubler.com/1.0/products.xml?token=96CC0E0A10851500F10431D64EC5585BFC8597DF")
Dim nodes As XmlNodeList = doc.SelectNodes("products/product")
rpMyRepeater.DataSource = nodes
rpMyRepeater.DataBind()
end if
end sub
</script>
<html>
<body>
<asp:repeater id="rpMyRepeater" runat="server">
<HeaderTemplate>
<Table border="0">
</HeaderTemplate>
<ItemTemplate>
<tr style="background-color:FFECD8">
<td>
<![CDATA[<%# DirectCast(Container.DataItem, System.Xml.XmlNode).Attributes("ns2:description").Value %>]]>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</Table>
</FooterTemplate>
</asp:repeater>
推荐答案
正如George所说，这是命名空间问题。不幸的是，XmlDocument类不容易使用XML命名空间，特别是对于具有默认命名空间的文档。您必须创建XmlNamespaceManager，显式添加名称空间，并为默认名称空间赋予前缀。
另外，查看源文档，您尝试检索的ns2：description是一个元素，因此您将无法在<$ c中找到它$ c>属性集合。
因为你需要XmlNamespaceManager来检索子元素，最简单的选项可能是将节点投影到Page_Load方法中的自定义类型。
As George said, this is a namespace issue. Unfortunately, theXmlDocumentclass doesn't make it easy to work with XML namespaces, and particularly with documents which have a default namespace. You have to create anXmlNamespaceManager, explicitly add the namespaces, and give the default namespace a prefix.
Also, looking at the source document, thens2:descriptionthat you're trying to retrieve is an element, so you won't be able to find it in theAttributescollection.
Since you need theXmlNamespaceManagerto retrieve the child elements, the simplest option is probably to project the nodes to a custom type in thePage_Loadmethod.
Dim doc As New XmlDocument()
doc.Load("http://api.tradedoubler.com/1.0/products.xml?token=96CC0E0A10851500F10431D64EC5585BFC8597DF")
Dim nsManager As New XmlNamespaceManager(doc.NameTable)
nsManager.AddNamespace("ns1", "urn:com:tradedoubler:pf:model:xml:output")
nsManager.AddNamespace("ns2", "urn:com:tradedoubler:pf:model:xml:common")
Dim nodes As XmlNodeList = doc.SelectNodes("//ns1:products/ns1:product", nsManager)
Dim dataSource As IEnumerable
dataSource = From node As XmlNode in nodes
Select Name = node.SelectSingleNode("ns2:name", nsManager).InnerText, _
Description = node.SelectSingleNode("ns2:description", nsManager).InnerText, _
Image = node.SelectSingleNode("ns2:productImage", nsManager).InnerText
rpMyRepeater.DataSource = dataSource
rpMyRepeater.DataBind()
<asp:repeater id="rpMyRepeater" runat="server">
<HeaderTemplate>
<table border="0">
</HeaderTemplate>
<ItemTemplate>
<tr style="background-color:FFECD8">
<td>
<%# Eval("Name") %>
</td>
<td>
<%# Eval("Description") %>
</td>
<td>
<asp:image runat="server"
ImageUrl='<%# Eval("Image") %>'
/>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:repeater>
注意：要使用LINQ查询，您可能需要导入 System.Linq 命名空间，如果它尚未导入 web.conf ig file：
NB: To use the LINQ query, you might need to import the System.Linq namespace, if it's not already imported in your web.config file:
<%@ Import Namespace="System.Linq" %>
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