我现在有一个XML文件:<?xml version="1.0" encoding="utf-8" ?>
<bookshop>
<book>
<name>love</name>
<price>25.9</price>
</book>
<book>
<name>success</name>
<price>30.00</price>
   </book>
<boo>
<name>放弃</name>
<price>53.0</price>
   </boo>
</bookshop>怎么通过C#来把名为success名书的价格改为50.0