对XML实现自定义、多字段排序 对Xml排序，除了使用XSLT之外，还可以使用XPathExpression类，但这些类一般情况下只支持数字和字符串类型的数据类型排序。要实现按照自己的排序方法排序，需要自己进行定义。AddSort 方法使用户能够按对象的数据类型（而不是按字符串或数字）将对象排序。IComparer 对象提供了 Compare 方法的实现，该实现支持按用户定义的类进行排序。
下面的例子就是实现自定义排序，并且支持多字段排序的一个例子。首先定义一个自定义对象，设置排序规则，然后使用XPathExpression.AddSort (Object, IComparer)方法进行排序。
<multistatus>
<response>
<objectGuid>{E4FCC019-CF62-4CA8-B9DA-184D19B62FBB}</objectGuid>
<href>/Portal/newpage/100063AF50C.vbs</href>
<displayname>100063AF50C.vbs</displayname>
<parentname>/Portal/newpage/</parentname>
<contentclass>urn:schemas-mengxianhui-cn:webpart</contentclass>
<getlastmodified>2004-11-05 09:13:58</getlastmodified>
<Title>新闻页面</Title>
<Author/>
</response>
<response>
<objectGuid>{661E575E-92A7-485C-B6B6-123BCE8377FC}</objectGuid>
<href>/Documents/home/images/shijian.gif</href>
<displayname>shijian.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2005-10-26 17:03:39</getlastmodified>
<createtime>9999-10-25 11:57:16</createtime>
<Title>shijian</Title>
<Author/>
<ItemOrder>2</ItemOrder>
</response>
<response>
<objectGuid>{661E575E-92A7-485C-B6B6-123BCE8377FC}</objectGuid>
<href>/Documents/home/images/shijian.gif</href>
<displayname>shijian.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2005-10-26 17:03:39</getlastmodified>
<createtime>2000-10-25 11:57:16</createtime>
<Title>孟子</Title>
<Author/>
<ItemOrder>2</ItemOrder>
</response>
<response>
<objectGuid>{661E575E-92A7-485C-B6B6-123BCE8377FC}</objectGuid>
<href>/Documents/home/images/shijian.gif</href>
<displayname>shijian.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2005-10-26 17:03:39</getlastmodified>
<createtime>2008-10-25 11:57:16</createtime>
<Title>孟宪会</Title>
<Author/>
<ItemOrder>2</ItemOrder>
</response>
<response>
<objectGuid>{C023513E-8877-4D63-8F11-5C1DB5CE6384}</objectGuid>
<href>/Documents/home/images/jiaoshizhijia.gif</href>
<displayname>jiaoshizhijia.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2003-10-26 17:03:39</getlastmodified>
<createtime>2002-10-22 16:38:02</createtime>
<Title>jiaoshizhijia</Title>
<ItemOrder>9</ItemOrder>
</response>
<response>
<objectGuid>{836BF9A3-32AE-48A5-B2AC-7525B9CCCEB3}</objectGuid>
<href>/Documents/home/images/leftbg.gif</href>
<displayname>leftbg.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2004-10-26 17:03:39</getlastmodified>
<createtime>2008-10-22 16:04:01</createtime>
<Title>leftbg</Title>
<ItemOrder>65</ItemOrder>
<Author/>
</response>
<response>
<objectGuid>{DECED835-84BC-4F15-860D-658AC14A51AE}</objectGuid>
<href>/Documents/home/images/zhuce.gif</href>
<displayname>zhuce.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2004-10-26 17:03:39</getlastmodified>
<createtime>2002-10-22 16:01:07</createtime>
<Title>zhuce</Title>
<Author/>
<ItemOrder>32</ItemOrder>
</response>
<response>
<objectGuid>{EF9B16D0-DB39-4034-B02A-B270C0436408}</objectGuid>
<href>/Documents/home/images/bbs.gif</href>
<displayname>bbs.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2004-10-26 17:03:39</getlastmodified>
<createtime>2005-10-22 16:01:03</createtime>
<Title>bbs</Title>
<Author/>
<ItemOrder>4</ItemOrder>
</response>
<response>
<objectGuid>{E105440A-1F58-41E4-A5A4-1194C09B8728}</objectGuid>
<href>/Documents/home/images/gonggao.gif</href>
<displayname>gonggao.gif</displayname>
<contentclass>urn:schemas-mengxianhui-cn:basedocument</contentclass>
<getlastmodified>2004-10-26 17:03:39</getlastmodified>
<createtime>2003-10-22 15:59:38</createtime>
<Title>gonggao</Title>
<Author/>
<ItemOrder>12</ItemOrder>
</response>
</multistatus>SortXml.aspx
<%@ Page Language="C#" %>
<script runat="server">
/// <summary>
/// 实现自定义排序的比较器，可按升序、降序排序
/// </summary>
public class DateTimeSort : System.Collections.IComparer
{
private SortType dataSortType;
public enum SortType { Asc, Desc };
int System.Collections.IComparer.Compare( Object x, Object y )
{
if (dataSortType == SortType.Asc)
{
return System.DateTime.Compare(System.Convert.ToDateTime(x), System.Convert.ToDateTime(y));
}
else
{
return System.DateTime.Compare(System.Convert.ToDateTime(y), System.Convert.ToDateTime(x));
}
}
public SortType DataSortType
{
set { dataSortType = value; }
}
}
protected void Page_Load( object sender, EventArgs e )
{
System.Xml.XPath.XPathDocument xpd = new System.Xml.XPath.XPathDocument(Server.MapPath("~/a.xml"));
System.Xml.XPath.XPathNavigator xpn = xpd.CreateNavigator();
System.Xml.XPath.XPathExpression xpe = xpn.Compile("/multistatus/response[position() > 1]/Title");
//设置排序字段和排序规则
DateTimeSort dts1 = new DateTimeSort();
dts1.DataSortType = DateTimeSort.SortType.Asc;
xpe.AddSort("../getlastmodified", dts1);
DateTimeSort dts2 = new DateTimeSort();
dts2.DataSortType = DateTimeSort.SortType.Desc;
xpe.AddSort("../createtime", dts2);
System.Xml.XPath.XPathNodeIterator nodeIter = xpn.Select(xpe);
Response.Write("<table border='0' cellspacing='1' cellpadding='3' style='background:#EEE;width:360px;font-size:12px;'>");
Response.Write("<tr style='background:#DDD'><td>第一排序字段</td><td>第二排序字段</td><td>标题</td></tr>");
while (nodeIter.MoveNext())
{
Response.Write("<tr style='background:#FFF'><td>" + nodeIter.Current.SelectSingleNode("../getlastmodified").Value + "</td><td>" + nodeIter.Current.SelectSingleNode("../createtime").Value + "</td><td>" + nodeIter.Current.Value + "</td></tr>");
}
Response.Write("</table>");
}
</script>
在使用 AddSort 方法时需要考虑的重要说明：
