xpath 随笔
由XmlDocument 对象创建的XPathNavigator 对象是可编辑的， 由XPathDocument 对象创建的XPathNavigator 对象是只读的。XPathNavigator 的 CanEdit 属性让您判断。
XPathDocument 对 XPath 和 XSLT 中的使用进行了优化，而且是只读模式，并且还可以在对xml文档运行XPath或者对内存中的xml运行XSLT的时候提供更好的性能。这些情况下，XPathDocument 应该在 XmlDocument之前优先考虑，只有在转换之前需要更新xml文档的时候才考虑使用XmlDocument.
xml格式的数据源有在前台有两种绑定形式，一种是<# XPath("key")> ，另一种是<%# XPathSelect("key") %>
下面举例说明：
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Xml" %>
<script runat="server">
private XmlDataDocument xd = new XmlDataDocument();
protected void Page_Load(object sender, EventArgs e)
{
xd.Load(Server.MapPath("XmlData.xml"));
Repeater1.DataSource = xd.SelectNodes("//site");
Repeater1.DataBind();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>XPath 方法绑定</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Repeater ID="Repeater1" runat="server">
<ItemTemplate>
<a href="<%#XPath("url") %>" title="<%#XPath("name")%>">
<%#XPath("img") == null ? XPath("name") : "<img src='" + XPath("img") + "' style='border:0px'>"%>
</a>
<br />
<br />
</ItemTemplate>
</asp:Repeater>
</form>
</body>
</html>
<?xml version="1.0" encoding="utf-8" ?>
<sites>
<site>
<name>.NET 开发者园地</name>
<url>http://dotnet.aspx.cc/</url>
<img>../images/logo.gif</img>
</site>
<site>
<name>.NET 技术交流社区</name>
<url>http://community.csdn.net/</url>
<img>../images/logo_csdn.gif</img>
</site>
<site>
<name>播客站点</name>
<url>http://blog.csdn.ent/net_lover/</url>
</site>
</sites>
<%@ Page Language="C#"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TemplateControl XPath and XPathSelect Example</title>
</head>
<body>
<h3>TemplateControl XPath Example</h3>
<form id="form1" runat="server">
<div>
<asp:XmlDataSource
id="XmlDataSource1"
runat="server"
XPath="contacts"
DataFile="contacts.xml" />
<asp:FormView
id="FormView1"
runat="server"
DataSourceID="XmlDataSource1">
<ItemTemplate>
<hr />
<asp:Repeater
id="Repeater1"
runat="server"
DataSource='<%# XPathSelect("contact") %>' >
<ItemTemplate>
Name: <%# XPath("name") %> <br />
Note: <%# XPath("note") %> <br />
<hr />
</ItemTemplate>
</asp:Repeater>
</ItemTemplate>
</asp:FormView>
</div>
</form>
</body>
</html>
<contacts>
<contact id="1">
<name>contact name 1</name>
<note>contact note 1</note>
</contact>
<contact id="2">
<name>contact name 2</name>
<note>contact note 2</note>
</contact>
</contacts>
XPathDocument 对 XPath 和 XSLT 中的使用进行了优化，而且是只读模式，并且还可以在对xml文档运行XPath或者对内存中的xml运行XSLT的时候提供更好的性能。这些情况下，XPathDocument 应该在 XmlDocument之前优先考虑，只有在转换之前需要更新xml文档的时候才考虑使用XmlDocument.
xml格式的数据源有在前台有两种绑定形式，一种是<# XPath("key")> ，另一种是<%# XPathSelect("key") %>
下面举例说明：
<%@ Page Language="C#" %><%@ Import Namespace="System.Xml" %><script runat="server"> private XmlDataDocument xd = new XmlDataDocument(); protected void Page_Load(object sender, EventArgs e) {
xd.Load(Server.MapPath("XmlData.xml")); Repeater1.DataSource = xd.SelectNodes("//site"); Repeater1.DataBind(); }</script><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"> <title>XPath 方法绑定</title></head><body> <form id="form1" runat="server"> <asp:Repeater ID="Repeater1" runat="server"> <ItemTemplate> <a href="<%#XPath("url") %>" title="<%#XPath("name")%>"> <%#XPath("img") == null ? XPath("name") : "<img src='" + XPath("img") + "' style='border:0px'>"%> </a> <br /> <br /> </ItemTemplate> </asp:Repeater> </form></body></html><?xml version="1.0" encoding="utf-8" ?><sites> <site> <name>.NET 开发者园地</name> <url>http://dotnet.aspx.cc/</url> <img>../images/logo.gif</img> </site> <site> <name>.NET 技术交流社区</name> <url>http://community.csdn.net/</url> <img>../images/logo_csdn.gif</img> </site> <site> <name>播客站点</name> <url>http://blog.csdn.ent/net_lover/</url> </site></sites><%@ Page Language="C#"%><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" ><head runat="server"> <title>TemplateControl XPath and XPathSelect Example</title></head><body> <h3>TemplateControl XPath Example</h3> <form id="form1" runat="server"> <div> <asp:XmlDataSource id="XmlDataSource1" runat="server" XPath="contacts" DataFile="contacts.xml" /> <asp:FormView id="FormView1" runat="server" DataSourceID="XmlDataSource1"> <ItemTemplate> <hr /> <asp:Repeater id="Repeater1" runat="server" DataSource='<%# XPathSelect("contact") %>' > <ItemTemplate> Name: <%# XPath("name") %> <br /> Note: <%# XPath("note") %> <br /> <hr /> </ItemTemplate> </asp:Repeater> </ItemTemplate> </asp:FormView> </div> </form></body></html><contacts> <contact id="1"> <name>contact name 1</name> <note>contact note 1</note> </contact> <contact id="2"> <name>contact name 2</name> <note>contact note 2</note> </contact></contacts>
