<?xml version="1.0" encoding="GB2312" ?>
<book>
    <title>XML 指南</title>
    <prod id="33-657" media="paper"></prod>
    <chapter>XML入门简介
        <para>什么是HTML</para>
        <para>什么是XML</para>
    </chapter>
    <chapter>XML语法
        <para>XML元素必须有结束标记</para>
        <para>XML元素必须正确地嵌套</para>
    </chapter>
</book>

<?php
/**
 * Created by PhpStorm.
 */

$xml = simplexml_load_file('book.xml');

echo $xml->chapter->para[0]."<br>";
echo $xml->chapter->para[1]."<br>";

$str = mb_convert_encoding('虾米大王','utf-8');
$xml->chapter->para[0] = $str;
$new_xml = $xml->asXML();
file_put_contents('newbook.xml',$new_xml);
echo "<hr>";
echo $xml->chapter->para[0]."<br>";
echo $xml->chapter->para[1]."<br>";