XML属性排序问题

[大可山人]

transform.xml文件：
--------------------
<?xml version="1.0" encoding="GB2312" ?>
<sales>
<summary>
<heading>Scootney Publishing</heading>
<subhead>Regional Sales Report</subhead>
<description>Sales report for the West Coast, Central and East Coast regions.</description>
</summary>
<link>
<source>http://www.vcsharp.com</source>
<label>VC#.COM Website</label>
</link>
<ulink source="http://www.vcsharp.net" label="VC#.Net网站"/>
<data>
<region>
<name>West Coast</name>
<quarter number="1" books_sold="24000" />
<quarter number="2" books_sold="38600" />
<quarter number="3" books_sold="44030" />
<quarter number="4" books_sold="21000" />
</region>
<region>
<name>Central</name>
<quarter number="1" books_sold="11000" />
<quarter number="2" books_sold="16080" />
<quarter number="3" books_sold="25000" />
<quarter number="4" books_sold="29000" />
</region>
<region>
<name>East Coast</name>
<quarter number="1" books_sold="27000" />
<quarter number="2" books_sold="31400" />
<quarter number="3" books_sold="40100" />
<quarter number="4" books_sold="30000" />
</region>
</data>
</sales>

sort.aspx
-----------------------
<%@ Page Language="C#" ContentType="text/html" ResponseEncoding="gb2312" %>
<%@ import namespace="System.Xml"%>
<%@ import namespace="System.Xml.XPath"%>
<Script runat="server">
private void Page_Load(object sender, System.EventArgs e)
{
StringBuilder unsorted = new StringBuilder();
StringBuilder sorted = new StringBuilder();
string xpath = "/sales/data/region/quarter/@books_sold";//用这句无法得到正常结果。为什么？
//上句如果是:string xpath = "/sales/data/region/name";可以得到正常结果

XPathDocument doc = new XPathDocument(Server.MapPath("transform.xml"));
XPathNavigator nav = doc.CreateNavigator();

XPathNodeIterator nodeIter1 = nav.Select(xpath);
while (nodeIter1.MoveNext()) {
unsorted.Append(nodeIter1.Current.Value + "<br />");
}
lblUnsorted.Text = unsorted.ToString();

XPathExpression exp = nav.Compile(xpath);
exp.AddSort("text()",XmlSortOrder.Descending,
XmlCaseOrder.None,"",XmlDataType.Number);

XPathNodeIterator nodeIter2 = nav.Select(exp);
while (nodeIter2.MoveNext()) {
sorted.Append(nodeIter2.Current.Value + "<br />");
}
lblSorted.Text = sorted.ToString();
}
</Script>
排序前：<br /><asp:Label runat="server" id="lblUnsorted"/><br/>
排序后：<br />
<font color="red">
<asp:Label runat="server" id="lblSorted"/>
</font>

[大可山人]

使用：string xpath = "/sales/data/region/quarter/@books_sold";//用这句无法得到正常结果：
排序前后结果均为：
24000
38600
44030
21000
11000
16080
25000
29000
27000
31400
40100
30000

使用：
string xpath = "/sales/data/region/name";
....
exp.AddSort("text()",XmlSortOrder.Descending,
XmlCaseOrder.None,"",XmlDataType.Text);//这里改成Text类型了
...则得到正常结果：
排序前：
West Coast
Central
East Coast

排序后：
West Coast
East Coast
Central

[saucer]

try

string xpath = "number(/sales/data/region/quarter/@books_sold)";

?

[saucer]

yes, you are right, actually, the problem is that you are using "text()", try ".":

exp.AddSort(".", XmlSortOrder.Descending,
XmlCaseOrder.None,"",XmlDataType.Number);

[大可山人]

照此法报错！

传递给此方法的表达式应产生 NodeSet。
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.Xml.XPath.XPathException: 传递给此方法的表达式应产生 NodeSet。

问题就是这句：XPathNodeIterator nodeIter1 = nav.Select(xpath);
而string xpath = "number(/sales/data/region/quarter/@books_sold)";
去掉number()不报错，但排序不正常。

[大可山人]

string xpath = "/sales/data/region/quarter/@books_sold";
...
exp.AddSort(".", XmlSortOrder.Descending,XmlCaseOrder.None,"",XmlDataType.Number);
...

OK!

Thanks saucer!