Objective C，一个关于 xpath 的问题

Question

<methodResponse>
    <params>
        <param>
            <value>
                <struct>
                    <member>
                        <name>topic_id</name>
                        <value>
                            <string>102</string>
                        </value>
                    </member>
                    <member>
                        <name>topic_title</name>
                        <value>
                            <string>Login test</string>
                        </value>
                    </member>
                </struct>
            </value>
        </param>
    </params>
</methodResponse>

我有这个xml..如何使用xpath获取topic_title的值？

Answer 1

/methodResponse
   /params
      /param
         /value
            /struct
              /member[name='topic_title']
                 /value
                    /string