C# XPath-选择两个节点之间的第一组同级_C#_Xml_Xpath_Siblings

C# XPath-选择两个节点之间的第一组同级

c# xml xpath

C# XPath-选择两个节点之间的第一组同级,c#,xml,xpath,siblings,C#,Xml,Xpath,Siblings,我在使用XPath查询C#中的一些HTML文件时遇到了一个小问题好的，首先是一个示例HTML： <table id="theTable"> <tbody> <tr class="theClass">A</tr> <tr class="theClass">B</tr> <tr>1</tr> <tr>2</tr&g

我在使用XPath查询C#中的一些HTML文件时遇到了一个小问题

好的，首先是一个示例HTML：

<table id="theTable">
    <tbody>
        <tr class="theClass">A</tr>
        <tr class="theClass">B</tr>
        <tr>1</tr>
        <tr>2</tr>
        <tr>3</tr>
        <tr>4</tr>
        <tr>5</tr>
        <tr class="theClass">C</tr>
        <tr class="theClass">D</tr>
        <tr>6</tr>
        <tr>7</tr>
        <tr>8</tr>
        <tr>9</tr>
        <tr>10</tr>
        <tr>11</tr>
        <tr>12</tr>
        <tr>13</tr>
        <tr>14</tr>
        <tr>15</tr>
        <tr class="theClass">E</tr>
        <tr class="theClass">F</tr>
        <tr>16</tr>
        <tr>17</tr>
        <tr>18</tr>
        <tr>19</tr>
        <tr>20</tr>
        <tr>21</tr>
        <tr>22</tr>
    </tbody>
</table>

这段代码在上面的HTML上运行，输出19和5。因此，只有第二个XPath表达式可以工作，但这仅仅是因为它搜索的元素前面有两个

class=theClass

，后面有4个

我的问题现在开始了。我想编写一个表达式，只返回

标记后面的第一组元素，不管后面还有多少组

如果我在这个HTML上运行我的代码

<table id="theTable">
    <tbody>
        <tr class="theClass">A</tr>
        <tr class="theClass">B</tr>
        <tr>1</tr>
        <tr>2</tr>
        <tr>3</tr>
        <tr>4</tr>
        <tr>5</tr>
        <tr>6</tr>
    </tbody>
</table>


A.
B
1.
2.
3.
4.
5.
6.

它将输出0和0

所以这不好

有人有什么想法吗

谢谢大家!

如果您不必使用XPath，某些LINQ可能更容易获得正确的结果，并且更具可读性

在您的情况下，Skip和类似于以下伪代码的组合可能会起作用：

nav.Select("//table[@id='theTable']/tbody/tr") // whatever to get list of all TR
   .Skip("theClass is B") // some condition to skip up to first node
   .TakeWhile("theClass is C"); // some condition to take upto second node.

现在，我要做的是只获取那些在

和

节点之间

使用这个XPath表达式：

   /*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]
  "/>
 </xsl:template>
</xsl:stylesheet>

   /*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]
  "/>
 </xsl:template>
</xsl:stylesheet>

<table id="theTable">
    <tbody>
        <tr class="theClass">A</tr>
        <tr class="theClass">B</tr>
        <tr>1</tr>
        <tr>2</tr>
        <tr>3</tr>
        <tr>4</tr>
        <tr>5</tr>
        <tr>6</tr>
    </tbody>
</table>

这里是一个基于XSLT的验证：

   /*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]
  "/>
 </xsl:template>
</xsl:stylesheet>

   /*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]
  "/>
 </xsl:template>
</xsl:stylesheet>

<table id="theTable">
    <tbody>
        <tr class="theClass">A</tr>
        <tr class="theClass">B</tr>
        <tr>1</tr>
        <tr>2</tr>
        <tr>3</tr>
        <tr>4</tr>
        <tr>5</tr>
        <tr>6</tr>
    </tbody>
</table>

其中，我们将

$ns1

替换为：

 /*/*/tr[.='B']
               /following-sibling::*

/*/*/tr[. ='C']/preceding-sibling::*

我们将$ns2替换为：

 /*/*/tr[.='B']
               /following-sibling::*

/*/*/tr[. ='C']/preceding-sibling::*

第二个问题：

   /*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]
  "/>
 </xsl:template>
</xsl:stylesheet>

   /*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]
  "/>
 </xsl:template>
</xsl:stylesheet>

<table id="theTable">
    <tbody>
        <tr class="theClass">A</tr>
        <tr class="theClass">B</tr>
        <tr>1</tr>
        <tr>2</tr>
        <tr>3</tr>
        <tr>4</tr>
        <tr>5</tr>
        <tr>6</tr>
    </tbody>
</table>

我的问题现在开始了。我想写一个表达式，它将只返回

标记后面的第一组元素，不管还有多少组跟着它

同样存在一个选择这些元素的XPath表达式：

   /*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]
  "/>
 </xsl:template>
</xsl:stylesheet>

   /*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]
  "/>
 </xsl:template>
</xsl:stylesheet>

<table id="theTable">
    <tbody>
        <tr class="theClass">A</tr>
        <tr class="theClass">B</tr>
        <tr>1</tr>
        <tr>2</tr>
        <tr>3</tr>
        <tr>4</tr>
        <tr>5</tr>
        <tr>6</tr>
    </tbody>
</table>

说明：

   /*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[.='B']
           /following-sibling::*
             [count(.|/*/*/tr[. ='C']/preceding-sibling::*)
             =
              count(/*/*/tr[. ='C']/preceding-sibling::*)
             ]
  "/>
 </xsl:template>
</xsl:stylesheet>

   /*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="/">
  <xsl:copy-of select=
  "/*/*/tr[@class='theClass'
         and
           following-sibling::*[1][self::tr[not(@*)] ]
           ][1]
             /following-sibling::tr
               [not(@*)
              and
                count(preceding-sibling::tr
                       [@class='theClass'
                      and
                        following-sibling::*[1][self::tr[not(@*)] ]
                       ]
                     )
                = 1
               ]
  "/>
 </xsl:template>
</xsl:stylesheet>

<table id="theTable">
    <tbody>
        <tr class="theClass">A</tr>
        <tr class="theClass">B</tr>
        <tr>1</tr>
        <tr>2</tr>
        <tr>3</tr>
        <tr>4</tr>
        <tr>5</tr>
        <tr>6</tr>
    </tbody>
</table>

这将选择第一个

*/*/tr

元素的所有后续同级

tr

元素（满足许多条件），该元素的

类

属性具有字符串值

“类”

，并且其第一个后续元素同级是没有属性的

tr

这些选定的

tr

元素也满足两个条件：1）它们没有任何属性；2）它们只有一个前面的同级

tr

元素，其

class

属性具有字符串值

“theClass”

下面是基于XSLT的验证：

/*/*/tr[.='B'] /following-sibling::* [count(.|/*/*/tr[. ='C']/preceding-sibling::*) = count(/*/*/tr[. ='C']/preceding-sibling::*) ]

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output omit-xml-declaration="yes" indent="yes"/> <xsl:template match="/"> <xsl:copy-of select= "/*/*/tr[.='B'] /following-sibling::* [count(.|/*/*/tr[. ='C']/preceding-sibling::*) = count(/*/*/tr[. ='C']/preceding-sibling::*) ] "/> </xsl:template> </xsl:stylesheet>

/*/*/tr[@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ][1] /following-sibling::tr [not(@*) and count(preceding-sibling::tr [@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ] ) = 1 ]

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output omit-xml-declaration="yes" indent="yes"/> <xsl:template match="/"> <xsl:copy-of select= "/*/*/tr[@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ][1] /following-sibling::tr [not(@*) and count(preceding-sibling::tr [@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ] ) = 1 ] "/> </xsl:template> </xsl:stylesheet>

<table id="theTable"> <tbody> <tr class="theClass">A</tr> <tr class="theClass">B</tr> <tr>1</tr> <tr>2</tr> <tr>3</tr> <tr>4</tr> <tr>5</tr> <tr>6</tr> </tbody> </table>

应用于第二个提供的XML文档时：

/*/*/tr[.='B'] /following-sibling::* [count(.|/*/*/tr[. ='C']/preceding-sibling::*) = count(/*/*/tr[. ='C']/preceding-sibling::*) ]

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output omit-xml-declaration="yes" indent="yes"/> <xsl:template match="/"> <xsl:copy-of select= "/*/*/tr[.='B'] /following-sibling::* [count(.|/*/*/tr[. ='C']/preceding-sibling::*) = count(/*/*/tr[. ='C']/preceding-sibling::*) ] "/> </xsl:template> </xsl:stylesheet>

/*/*/tr[@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ][1] /following-sibling::tr [not(@*) and count(preceding-sibling::tr [@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ] ) = 1 ]

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output omit-xml-declaration="yes" indent="yes"/> <xsl:template match="/"> <xsl:copy-of select= "/*/*/tr[@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ][1] /following-sibling::tr [not(@*) and count(preceding-sibling::tr [@class='theClass' and following-sibling::*[1][self::tr[not(@*)] ] ] ) = 1 ] "/> </xsl:template> </xsl:stylesheet>

<table id="theTable"> <tbody> <tr class="theClass">A</tr> <tr class="theClass">B</tr> <tr>1</tr> <tr>2</tr> <tr>3</tr> <tr>4</tr> <tr>5</tr> <tr>6</tr> </tbody> </table>

A. B 1. 2. 3. 4. 5. 6.
再次输出所需和正确选择的元素：

<table id="theTable"> <tbody> <tr class="theClass">A</tr> <tr class="theClass">B</tr> <tr>1</tr> <tr>2</tr> <tr>3</tr> <tr>4</tr> <tr>5</tr> <tr class="theClass">C</tr> <tr class="theClass">D</tr> <tr>6</tr> <tr>7</tr> <tr>8</tr> <tr>9</tr> <tr>10</tr> <tr>11</tr> <tr>12</tr> <tr>13</tr> <tr>14</tr> <tr>15</tr> <tr class="theClass">E</tr> <tr class="theClass">F</tr> <tr>16</tr> <tr>17</tr> <tr>18</tr> <tr>19</tr> <tr>20</tr> <tr>21</tr> <tr>22</tr> </tbody> </table>

<tr>1</tr> <tr>2</tr> <tr>3</tr> <tr>4</tr> <tr>5</tr>

<tr>1</tr> <tr>2</tr> <tr>3</tr> <tr>4</tr> <tr>5</tr> <tr>6</tr>

1 2. 3. 4. 5. 6.
我不明白你的意思。预期的结果是什么？@ChuckSavage我希望第一个HTML返回元素1,2,3,4,5，第二个HTML返回元素elemenets 1,2,3,4,5,6。非常感谢，它很有效。你能解释一下最后的表达方式吗？我不确定我是否理解它。谢谢大家!@不客气。我编辑了答案，并为这两种表达添加了解释。