如何：查找具有特定元素名称的子代
更新：November 2007
有时，您想要查找所有具有特定名称的子代。 可以编写代码用于循环访问所有子代，但使用 Descendants 轴更简单。
示例
下面的示例演示如何根据元素名称查找子代。
XElement root = XElement.Parse(@"<root>
<para>
<r>
<t>Some text </t>
</r>
<n>
<r>
<t>that is broken up into </t>
</r>
</n>
<n>
<r>
<t>multiple segments.</t>
</r>
</n>
</para>
</root>");
IEnumerable<string> textSegs =
from seg in root.Descendants("t")
select (string)seg;
string str = textSegs.Aggregate(new StringBuilder(),
(sb, i) => sb.Append(i),
sp => sp.ToString()
);
Console.WriteLine(str);
Dim root As XElement = _
<root>
<para>
<r>
<t>Some text </t>
</r>
<n>
<r>
<t>that is broken up into </t>
</r>
</n>
<n>
<r>
<t>multiple segments.</t>
</r>
</n>
</para>
</root>
Dim textSegs As IEnumerable(Of String) = _
From seg In root...<t> _
Select seg.Value
Dim str As String = textSegs.Aggregate( _
New StringBuilder, _
Function(sb, i) sb.Append(i), _
Function(sb) sb.ToString)
Console.WriteLine(str)
此代码生成以下输出：
Some text that is broken up into multiple segments.
下面的示例演示如何对命名空间中的 XML 进行同样的查询。 有关更多信息，请参见使用 XML 命名空间。
XElement root = XElement.Parse(@"<root xmlns='http://www.adatum.com'>
<para>
<r>
<t>Some text </t>
</r>
<n>
<r>
<t>that is broken up into </t>
</r>
</n>
<n>
<r>
<t>multiple segments.</t>
</r>
</n>
</para>
</root>");
XNamespace ad = "http://www.adatum.com";
IEnumerable<string> textSegs =
from seg in root.Descendants(ad + "t")
select (string)seg;
string str = textSegs.Aggregate(new StringBuilder(),
(sb, i) => sb.Append(i),
sp => sp.ToString()
);
Console.WriteLine(str);
Imports <xmlns='http://www.adatum.com'>
Module Module1
Sub Main()
Dim root As XElement = _
<root>
<para>
<r>
<t>Some text </t>
</r>
<n>
<r>
<t>that is broken up into </t>
</r>
</n>
<n>
<r>
<t>multiple segments.</t>
</r>
</n>
</para>
</root>
Dim textSegs As IEnumerable(Of String) = _
From seg In root...<t> _
Select seg.Value
Dim str As String = textSegs.Aggregate( _
New StringBuilder, _
Function(sb, i) sb.Append(i), _
Function(sb) sb.ToString)
Console.WriteLine(str)
End Sub
End Module
此代码生成以下输出：
Some text that is broken up into multiple segments.