C＃中的初学者XPath表达式错误

Question

I am trying to use following XPath expressions:

nodeList = root.SelectNodes("/moviedb/movie[genres="Thriller"]");
nodeList = root.SelectNodes("/moviedb/movie[contains(genres, "+ ElementValue +")]");

where ElementValue is user input value

For the first line i get errors like:

Error 4 ) expected
Error 6 Invalid expression term ')'

While second expression returns 0

Before i used this expressions in the c#, i did test them online and they worked. My xml looks something like this:

<moviedb>
<movie>
    <imdbid>tt2226321</imdbid>
    <genres>Thriller</genres>
    <languages>English</languages>
    <country>USA</country>
    <rating>8</rating>
    <runtime>155</runtime>
    <title>The Dark Knight</title>
    <year>2014</year>
  </movie>
  <movie>
    <imdbid>tt1959490</imdbid>
    <genres>Action,Adventure,Drama</genres>
    <languages>English</languages>                                        
    <country>USA</country>
    <rating>6.5</rating>
    <runtime>138</runtime>
    <title>Noah</title>
    <year>2014</year>
  </movie>
</moviedb>

Thanks

Answer 1

When dealing with quotes in strings you need to take special steps, as inserting any quotes will make the compiler think you are ending or starting a new string.

Either use the \\" escape sequence to show the compiler that you mean to insert a quote mark instead of the end of a string, or the @ symbol and use 2 double quotes ( "" )

nodeList = root.SelectNodes(@"/moviedb/movie[genres=""Thriller""]");

or

nodeList = root.SelectNodes("/moviedb/movie[genres=\"Thriller\"]");