XPath简单教程

原文地址 http://www.cnblogs.com/ipointer/

/AAA

选择根元素AAA


     <
AAA>
          <BBB/>
          <CCC/>
          <BBB/>
          <BBB/>
          <DDD>
               <BBB/>
          </DDD>
          <CCC/>
     </
AAA>

 

/AAA/CCC

选择AAA的所有CCC子元素


     <AAA>
          <BBB/>
          <
CCC/>
          <BBB/>
          <BBB/>
          <DDD>
               <BBB/>
          </DDD>
          <
CCC/>
     </AAA>

 

/AAA/DDD/BBB

选择AAA的子元素DDD的所有子元素


     <AAA>
          <BBB/>
          <CCC/>
          <BBB/>
          <BBB/>
          <DDD>
               <
BBB/>
          </DDD>
          <CCC/>
     </AAA>

 

 

实例 2

如果路径以双斜线 // 开头, 则表示选择文档中所有满足双斜线//之后规则的元素(无论层级关系)

 

//BBB

选择所有BBB元素


     <AAA>
          <
BBB/>
          <CCC/>
          <
BBB/>
          <DDD>
               <
BBB/>
          </DDD>
          <CCC>
               <DDD>
                    <
BBB/>
                    <
BBB/>
               </DDD>
          </CCC>
     </AAA>

 

//DDD/BBB

选择所有父元素是DDDBBB元素


     <AAA>
          <BBB/>
          <CCC/>
          <BBB/>
          <DDD>
               <
BBB/>
          </DDD>
          <CCC>
               <DDD>
                    <
BBB/>
                    <
BBB/>
               </DDD>
          </CCC>
     </AAA>

 

 

实例 3

星号 * 表示选择所有由星号之前的路径所定位的元素

 

/AAA/CCC/DDD/*

选择所有路径依附于/AAA/CCC/DDD的元素


     <AAA>
          <XXX>
               <DDD>
                    <BBB/>
                    <BBB/>
                    <EEE/>
                    <FFF/>
               </DDD>
          </XXX>
          <CCC>
               <DDD>
                    <
BBB/>
                    <
BBB/>
                    <
EEE/>
                    <
FFF/>
               </DDD>
          </CCC>
          <CCC>
               <BBB>
                    <BBB>
                         <BBB/>
                    </BBB>
               </BBB>
          </CCC>
     </AAA>

 

/*/*/*/BBB

选择所有的有3个祖先元素的BBB元素


     <AAA>
          <XXX>
               <DDD>
                    <
BBB/>
                    <
BBB/>
                    <EEE/>
                    <FFF/>
               </DDD>
          </XXX>
          <CCC>
               <DDD>
                    <
BBB/>
                    <
BBB/>
                    <EEE/>
                    <FFF/>
               </DDD>
          </CCC>
          <CCC>
               <BBB>
                    <
BBB>
                         <BBB/>
                    </
BBB>
               </BBB>
          </CCC>
     </AAA>

 

//*

选择所有元素


     <
AAA>
          <
XXX>
               <
DDD>
                    <
BBB/>
                    <
BBB/>
                    <
EEE/>
                    <
FFF/>
               </
DDD>
          </
XXX>
          <
CCC>
               <
DDD>
                    <
BBB/>
                    <
BBB/>
                    <
EEE/>
                    <
FFF/>
               </
DDD>
          </
CCC>
          <
CCC>
               <
BBB>
                    <
BBB>
                         <
BBB/>
                    </
BBB>
               </
BBB>
          </
CCC>
     </
AAA>

 

 

 

实例 4

方块号里的表达式可以进一步的指定元素, 其中数字表示元素在选择集里的位置, last()函数则表示选择集中的最后一个元素.

 

/AAA/BBB[1]

选择AAA的第一个BBB子元素


     <AAA>
          <
BBB/>
          <BBB/>
          <BBB/>
          <BBB/>
     </AAA>

 

/AAA/BBB[last()]

选择AAA的最后一个BBB子元素


     <AAA>
          <BBB/>
          <BBB/>
          <BBB/>
          <
BBB/>
     </AAA>

 

 

 

实例 5

//@id

选择所有的id属性


     <AAA>
          <BBB
id = "b1"/>
          <BBB
id = "b2"/>
          <BBB name = "bbb"/>
          <BBB/>
     </AAA>

 

//BBB[@id]

选择有id属性的BBB元素


     <AAA>
          <
BBB id = "b1"/>
          <
BBB id = "b2"/>
          <BBB name = "bbb"/>
          <BBB/>
     </AAA>

 

//BBB[@name]

选择有name属性的BBB元素


     <AAA>
          <BBB id = "b1"/>
          <BBB id = "b2"/>
          <
BBB name = "bbb"/>
          <BBB/>
     </AAA>

 

//BBB[@*]

选择有任意属性的BBB元素


     <AAA>
          <
BBB id = "b1"/>
          <
BBB id = "b2"/>
          <
BBB name = "bbb"/>
          <BBB/>
     </AAA>

 

//BBB[not(@*)]

选择没有属性的BBB元素


     <AAA>
          <BBB id = "b1"/>
          <BBB id = "b2"/>
          <BBB name = "bbb"/>
          <
BBB/>
     </AAA>

 

 

 

实例 6

属性的值可以被用来作为选择的准则, normalize-space函数删除了前部和尾部的空格, 并且把连续的空格串替换为一个单一的空格

 

//BBB[@id='b1']

选择含有属性id且其值为'b1'BBB元素


     <AAA>
          <
BBB id = "b1"/>
          <BBB name = " bbb "/>
          <BBB name = "bbb"/>
     </AAA>

 

//BBB[@name='bbb']

选择含有属性name且其值为'bbb'BBB元素


     <AAA>
          <BBB id = "b1"/>
          <BBB name = " bbb "/>
          <
BBB name = "bbb"/>
     </AAA>

 

//BBB[normalize-space(@name)='bbb']

选择含有属性name且其值(在用normalize-space函数去掉前后空格后)'bbb'BBB元素


     <AAA>
          <BBB id = "b1"/>
          <
BBB name = " bbb "/>
          <
BBB name = "bbb"/>
     </AAA>

 

 

 

实例 7

count()函数可以计数所选元素的个数

 

//*[count(BBB)=2]

选择含有2BBB子元素的元素


     <AAA>
          <CCC>
               <BBB/>
               <BBB/>
               <BBB/>
          </CCC>
          <
DDD>
               <BBB/>
               <BBB/>
          </
DDD>
          <EEE>
               <CCC/>
               <DDD/>
          </EEE>
     </AAA>

 

//*[count(*)=2]

选择含有2个子元素的元素


     <AAA>
          <CCC>
               <BBB/>
               <BBB/>
               <BBB/>
          </CCC>
          <
DDD>
               <BBB/>
               <BBB/>
          </
DDD>
          <
EEE>
               <CCC/>
               <DDD/>
          </
EEE>
     </AAA>

 

//*[count(*)=3]

选择含有3个子元素的元素


     <
AAA>
          <
CCC>
               <BBB/>
               <BBB/>
               <BBB/>
          </
CCC>
          <DDD>
               <BBB/>
               <BBB/>
          </DDD>
          <EEE>
               <CCC/>
               <DDD/>
          </EEE>
     </
AAA>

 

 

 

实例 8

name()函数返回元素的名称, start-with()函数在该函数的第一个参数字符串是以第二个参数字符开始的情况返回true, contains()函数当其第一个字符串参数包含有第二个字符串参数时返回true.

 

//*[name()='BBB']

选择所有名称为BBB的元素(这里等价于//BBB)


     <AAA>
          <BCC>
               <
BBB/>
               <
BBB/>
               <
BBB/>
          </BCC>
          <DDB>
               <
BBB/>
               <
BBB/>
          </DDB>
          <BEC>
               <CCC/>
               <DBD/>
          </BEC>
     </AAA>

 

//*[starts-with(name(),'B')]

选择所有名称以"B"起始的元素


     <AAA>
          <
BCC>
               <
BBB/>
               <
BBB/>
               <
BBB/>
          </
BCC>
          <DDB>
               <
BBB/>
               <
BBB/>
          </DDB>
          <
BEC>
               <CCC/>
               <DBD/>
          </
BEC>
     </AAA>

 

//*[contains(name(),'C')]

选择所有名称包含"C"的元素


     <AAA>
          <
BCC>
               <BBB/>
               <BBB/>
               <BBB/>
          </
BCC>
          <DDB>
               <BBB/>
               <BBB/>
          </DDB>
          <
BEC>
               <
CCC/>
               <DBD/>
          </
BEC>
     </AAA>

 

 

 

实例 10

多个路径可以用分隔符 | 合并在一起

 

//CCC | //BBB

选择所有的CCCBBB元素


     <AAA>
          <
BBB/>
          <
CCC/>
          <DDD>
               <
CCC/>
          </DDD>
          <EEE/>
     </AAA>

 

/AAA/EEE | //BBB

选择所有的BBB元素和所有是AAA的子元素的EEE元素


     <AAA>
          <
BBB/>
          <CCC/>
          <DDD>
               <CCC/>
          </DDD>
          <
EEE/>
     </AAA>

 

/AAA/EEE | //DDD/CCC | /AAA | //BBB

可以合并的路径数目没有限制


     <
AAA>
          <
BBB/>
          <CCC/>
          <DDD>
               <
CCC/>
          </DDD>
          <
EEE/>
     </
AAA>

 

 

 

实例 11

child(axis)包含上下文节点的子元素, 作为默认的轴,可以忽略不写.

 

/AAA

等价于 /child::AAA


     <
AAA>
          <BBB/>
          <CCC/>
     </
AAA>

 

/child::AAA

等价于/AAA


     <
AAA>
          <BBB/>
          <CCC/>
     </
AAA>

 

/AAA/BBB

等价于/child::AAA/child::BBB


     <AAA>
          <
BBB/>
          <CCC/>
     </AAA>

 

/child::AAA/child::BBB

等价于/AAA/BBB


     <AAA>
          <
BBB/>
          <CCC/>
     </AAA>

 

/child::AAA/BBB

二者都可以被合并


     <AAA>
          <
BBB/>
          <CCC/>
     </AAA>

 

 

 

 

实例 12

descendant (后代)轴包含上下文节点的后代,一个后代是指子节点或者子节点的子节点等等, 因此descendant轴不会包含属性和命名空间节点.

 

/descendant::*

选择文档根元素的所有后代.即所有的元素被选择


     <
AAA>
          <
BBB>
               <
DDD>
                    <
CCC>
                         <
DDD/>
                         <
EEE/>
                    </
CCC>
               </
DDD>
          </
BBB>
          <
CCC>
               <
DDD>
                    <
EEE>
                         <
DDD>
                              <
FFF/>
                         </
DDD>
                    </
EEE>
               </
DDD>
          </
CCC>
     </
AAA>

 

/AAA/BBB/descendant::*

选择/AAA/BBB的所有后代元素


     <AAA>
          <BBB>
               <
DDD>
                    <
CCC>
                         <
DDD/>
                         <
EEE/>
                    </
CCC>
               </
DDD>
          </BBB>
          <CCC>
               <DDD>
                    <EEE>
                         <DDD>
                              <FFF/>
                         </DDD>
                    </EEE>
               </DDD>
          </CCC>
     </AAA>

 

//CCC/descendant::*

选择在祖先元素中有CCC的所有元素


     <AAA>
          <BBB>
               <DDD>
                    <CCC>
                         <
DDD/>
                         <
EEE/>
                    </CCC>
               </DDD>
          </BBB>
          <CCC>
               <
DDD>
                    <
EEE>
                         <
DDD>
                              <
FFF/>
                         </
DDD>
                    </
EEE>
               </
DDD>
          </CCC>
     </AAA>

 

 

原文地址 http://www.cnblogs.com/ipointer/

 

//CCC/descendant::DDD

选择所有以CCC为祖先元素的DDD元素


     <AAA>
          <BBB>
               <DDD>
                    <CCC>
                         <
DDD/>
                         <EEE/>
                    </CCC>
               </DDD>
          </BBB>
          <CCC>
               <
DDD>
                    <EEE>
                         <
DDD>
                              <FFF/>
                         </
DDD>
                    </EEE>
               </
DDD>
          </CCC>
     </AAA>

 

 

 

 

实例 13

parent(axis)包含上下文节点的父节点, 如果有父节点的话

 

//DDD/parent::*

选择DDD元素的所有父节点


     <AAA>
          <
BBB>
               <DDD>
                    <
CCC>
                         <DDD/>
                         <EEE/>
                    </
CCC>
               </DDD>
          </
BBB>
          <
CCC>
               <DDD>
                    <
EEE>
                         <DDD>
                              <FFF/>
                         </DDD>
                    </
EEE>
               </DDD>
          </
CCC>
     </AAA>

 

 

 

 

实例 14

ancestor(axis)包含上下节点的祖先节点, 该祖先节点由其上下文节点的父节点以及父节点的父节点等等诸如此类的节点构成,所以ancestor轴总是包含有根节点,除非上下文节点就是根节点本身.

 

/AAA/BBB/DDD/CCC/EEE/ancestor::*

选择一个绝对路径上的所有节点


     <
AAA>
          <
BBB>
               <
DDD>
                    <
CCC>
                         <DDD/>
                         <EEE/>
                    </
CCC>
               </
DDD>
          </
BBB>
          <CCC>
               <DDD>
                    <EEE>
                         <DDD>
                              <FFF/>
                         </DDD>
                    </EEE>
               </DDD>
          </CCC>
     </
AAA>

 

//FFF/ancestor::*

选择FFF元素的祖先节点


     <
AAA>
          <BBB>
               <DDD>
                    <CCC>
                         <DDD/>
                         <EEE/>
                    </CCC>
               </DDD>
          </BBB>
          <
CCC>
               <
DDD>
                    <
EEE>
                         <
DDD>
                              <FFF/>
                         </
DDD>
                    </
EEE>
               </
DDD>
          </
CCC>
     </
AAA>

 

 

 

 

实例 15

following-sibling(axis)包含上下文节点之后的所有兄弟节点

 

/AAA/BBB/following-sibling::*

 


     <AAA>
          <BBB>
               <CCC/>
               <DDD/>
          </BBB>
          <
XXX>
               <DDD>
                    <EEE/>
                    <DDD/>
                    <CCC/>
                    <FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </DDD>
          </
XXX>
          <
CCC>
               <DDD/>
          </
CCC>
     </AAA>

 

//CCC/following-sibling::*

 


     <AAA>
          <BBB>
               <CCC/>
               <
DDD/>
          </BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <DDD/>
                    <CCC/>
                    <
FFF/>
                    <
FFF>
                         <GGG/>
                    </
FFF>
               </DDD>
          </XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

 

 

 

实例 16

preceding-sibling (axis)包含上下文节点之前的所有兄弟节点

 

/AAA/XXX/preceding-sibling::*

 


     <AAA>
          <
BBB>
               <CCC/>
               <DDD/>
          </
BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <DDD/>
                    <CCC/>
                    <FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </DDD>
          </XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

//CCC/preceding-sibling::*

 


     <AAA>
          <
BBB>
               <CCC/>
               <DDD/>
          </
BBB>
          <
XXX>
               <DDD>
                    <
EEE/>
                    <
DDD/>
                    <CCC/>
                    <FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </DDD>
          </
XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

 

 

 

实例 17

following(axis)包含同一文档中按文档顺序位于上下文节点之后的所有节点, 除了祖先节点,属性节点和命名空间节点

 

/AAA/XXX/following::*

 


     <AAA>
          <BBB>
               <CCC/>
               <ZZZ>
                    <DDD/>
                    <DDD>
                         <EEE/>
                    </DDD>
               </ZZZ>
               <FFF>
                    <GGG/>
               </FFF>
          </BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <DDD/>
                    <CCC/>
                    <FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </DDD>
          </XXX>
          <
CCC>
               <
DDD/>
          </
CCC>
     </AAA>

 

//ZZZ/following::*

 


     <AAA>
          <BBB>
               <CCC/>
               <ZZZ>
                    <DDD/>
                    <DDD>
                         <EEE/>
                    </DDD>
               </ZZZ>
               <
FFF>
                    <
GGG/>
               </
FFF>
          </BBB>
          <
XXX>
               <
DDD>
                    <
EEE/>
                    <
DDD/>
                    <
CCC/>
                    <
FFF/>
                    <
FFF>
                         <
GGG/>
                    </
FFF>
               </
DDD>
          </
XXX>
          <
CCC>
               <
DDD/>
          </
CCC>
     </AAA>

 

 

 

 

实例 18

preceding(axis)包含同一文档中按文档顺序位于上下文节点之前的所有节点, 除了祖先节点,属性节点和命名空间节点

 

/AAA/XXX/preceding::*

 


     <AAA>
          <
BBB>
               <
CCC/>
               <
ZZZ>
                    <
DDD/>
               </
ZZZ>
          </
BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <DDD/>
                    <CCC/>
                    <FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </DDD>
          </XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

//GGG/preceding::*

 


     <AAA>
          <
BBB>
               <
CCC/>
               <
ZZZ>
                    <
DDD/>
               </
ZZZ>
          </
BBB>
          <XXX>
               <DDD>
                    <
EEE/>
                    <
DDD/>
                    <
CCC/>
                    <
FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </DDD>
          </XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

 

 

 

实例 19

descendant-or-self (axis)包含上下文节点本身和该节点的后代节点

 

/AAA/XXX/descendant-or-self::*

 


     <AAA>
          <BBB>
               <CCC/>
               <ZZZ>
                    <DDD/>
               </ZZZ>
          </BBB>
          <
XXX>
               <
DDD>
                    <
EEE/>
                    <
DDD/>
                    <
CCC/>
                    <
FFF/>
                    <
FFF>
                         <
GGG/>
                    </
FFF>
               </
DDD>
          </
XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

//CCC/descendant-or-self::*

 


     <AAA>
          <BBB>
               <
CCC/>
               <ZZZ>
                    <DDD/>
               </ZZZ>
          </BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <DDD/>
                    <
CCC/>
                    <FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </DDD>
          </XXX>
          <
CCC>
               <
DDD/>
          </
CCC>
     </AAA>

 

 

 

 

实例 20

ancestor-or-self (axis)包含上下文节点本身和该节点的祖先节点

 

/AAA/XXX/DDD/EEE/ancestor-or-self::*

 


     <
AAA>
          <BBB>
               <CCC/>
               <ZZZ>
                    <DDD/>
               </ZZZ>
          </BBB>
          <
XXX>
               <
DDD>
                    <
EEE/>
                    <DDD/>
                    <CCC/>
                    <FFF/>
                    <FFF>
                         <GGG/>
                    </FFF>
               </
DDD>
          </
XXX>
          <CCC>
               <DDD/>
          </CCC>
     </
AAA>

 

//GGG/ancestor-or-self::*

 


     <
AAA>
          <BBB>
               <CCC/>
               <ZZZ>
                    <DDD/>
               </ZZZ>
          </BBB>
          <
XXX>
               <
DDD>
                    <EEE/>
                    <DDD/>
                    <CCC/>
                    <FFF/>
                    <
FFF>
                         <
GGG/>
                    </
FFF>
               </
DDD>
          </
XXX>
          <CCC>
               <DDD/>
          </CCC>
     </
AAA>

 

 

 

 

实例 21

ancestor, descendant, following, preceding self(axis)分割了XML文档(忽略属性节点和命名空间节点), 不能交迭, 而一起使用则包含所有节点

 

//GGG/ancestor::*

 


     <
AAA>
          <BBB>
               <CCC/>
               <ZZZ/>
          </BBB>
          <
XXX>
               <
DDD>
                    <EEE/>
                    <
FFF>
                         <HHH/>
                         <GGG>
                              <JJJ>
                                   <QQQ/>
                              </JJJ>
                              <JJJ/>
                         </GGG>
                         <HHH/>
                    </
FFF>
               </
DDD>
          </
XXX>
          <CCC>
               <DDD/>
          </CCC>
     </
AAA>

 

//GGG/descendant::*

 


     <AAA>
          <BBB>
               <CCC/>
               <ZZZ/>
          </BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <FFF>
                         <HHH/>
                         <GGG>
                              <
JJJ>
                                   <
QQQ/>
                              </
JJJ>
                              <
JJJ/>
                         </GGG>
                         <HHH/>
                    </FFF>
               </DDD>
          </XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

//GGG/following::*

 


     <AAA>
          <BBB>
               <CCC/>
               <ZZZ/>
          </BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <FFF>
                         <HHH/>
                         <GGG>
                              <JJJ>
                                   <QQQ/>
                              </JJJ>
                              <JJJ/>
                         </GGG>
                         <
HHH/>
                    </FFF>
               </DDD>
          </XXX>
          <
CCC>
               <
DDD/>
          </
CCC>
     </AAA>

 

//GGG/preceding::*

 


     <AAA>
          <
BBB>
               <
CCC/>
               <
ZZZ/>
          </
BBB>
          <XXX>
               <DDD>
                    <
EEE/>
                    <FFF>
                         <
HHH/>
                         <GGG>
                              <JJJ>
                                   <QQQ/>
                              </JJJ>
                              <JJJ/>
                         </GGG>
                         <HHH/>
                    </FFF>
               </DDD>
          </XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

//GGG/self::*

 


     <AAA>
          <BBB>
               <CCC/>
               <ZZZ/>
          </BBB>
          <XXX>
               <DDD>
                    <EEE/>
                    <FFF>
                         <HHH/>
                         <
GGG>
                              <JJJ>
                                   <QQQ/>
                              </JJJ>
                              <JJJ/>
                         </
GGG>
                         <HHH/>
                    </FFF>
               </DDD>
          </XXX>
          <CCC>
               <DDD/>
          </CCC>
     </AAA>

 

//GGG/ancestor::* | //GGG/descendant::* | //GGG/following::* | //GGG/preceding::* | //GGG/self::*

 


     <
AAA>
          <
BBB>
               <
CCC/>
               <
ZZZ/>
          </
BBB>
          <
XXX>
               <
DDD>
                    <
EEE/>
                    <
FFF>
                         <
HHH/>
                         <
GGG>
                              <
JJJ>
                                   <
QQQ/>
                              </
JJJ>
                              <
JJJ/>
                         </
GGG>
                         <
HHH/>
                    </
FFF>
               </
DDD>
          </
XXX>
          <
CCC>
               <
DDD/>
          </
CCC>
     </
AAA>

 

 

 

 

实例 22

div运算符做浮点除法运算, mod运算符做求余运算, floor函数返回不大于参数的最大整数(趋近于正无穷), ceiling返回不小于参数的最小整数(趋近于负无穷)

 

//BBB[position() mod 2 = 0 ]

选择偶数位置的BBB元素


     <AAA>
          <BBB/>
          <
BBB/>
          <BBB/>
          <
BBB/>
          <BBB/>
          <
BBB/>
          <BBB/>
          <
BBB/>
          <CCC/>
          <CCC/>
          <CCC/>
     </AAA>

 

//BBB[ position() = floor(last() div 2 + 0.5) or position() = ceiling(last() div 2 + 0.5) ]

选择中间的BBB元素


     <AAA>
          <BBB/>
          <BBB/>
          <BBB/>
          <
BBB/>
          <
BBB/>
          <BBB/>
          <BBB/>
          <BBB/>
          <CCC/>
          <CCC/>
          <CCC/>
     </AAA>

 

//CCC[ position() = floor(last() div 2 + 0.5) or position() = ceiling(last() div 2 + 0.5) ]

选择中间的CCC元素


     <AAA>
          <BBB/>
          <BBB/>
          <BBB/>
          <BBB/>
          <BBB/>
          <BBB/>
          <BBB/>
          <BBB/>
          <CCC/>
          <
CCC/>
          <CCC/>
     </AAA>

 

posted @ 2007-12-07 17:31  ZetaChow晓代码  阅读(236)  评论(0编辑  收藏  举报