Xpath for selecting html id including random number

问题

Hi how would I select all link when they have the following id.

<a id="List_ctl01_link3" class="content" href=link1.aspx">
<a id="List_ctl02_link3" class="content" href=link2.aspx">
<a id="List_ctl03_link3" class="content" href=link3.aspx">
<a id="List_ctl04_link3" class="content" href=link4.aspx">

And so on...

Please note that the last part "link3" is important, and must be included in the Xpath.

I'm using C# and Html agility pack.

回答1:

In case you use xpath 2.0 you can try match/matches functions and use regular expressions. If you are with xpath 1.0 probably you will have to write your custom attribute parser (take a look at xsl:function). AFAIR the match function is available only xpath 2.0.

Probably @id[starts-with(., 'List_ct') and ends-with(., 'link3')] is another way to do it.

回答2:

Hi how would I select all link when they have the following id

Use this XPath expression:

//a[@id[starts-with(.,'List_ctl')][substring(.,string-length()-5)='_link3']]

Note: There is no fn:ends-with() in XPath 1.0. Use last predicate instead.

回答3:

Use:

//a[@id[starts-with(.,'List_ctl')
      and
        substring(.,string-length()-5)='_link3'
      and
         floor(substring-before(substring_after(.,'List_ctl'),'_'))
        =
         floor(substring-before(substring_after(.,'List_ctl'),'_'))
       ]
   ]

This XPath expression selects all a elements in the document whose id attribute has string value with all of the following properties:

1. Starts with the string 'List_ctl' .

2. Ends with the string '_link3' .

3. The substring surrounded by 'List_ctl' and '_' is a representation of an integer.

来源：https://stackoverflow.com/questions/4142575/xpath-for-selecting-html-id-including-random-number