Simple happiness

想写一个提取照片的插件，虽然我不懂PHP，不懂XML，但知道谷歌与开源的力量强大，于是乎“无知者无畏”。没想到再次被击得晕头转向了。
能够读取XML了，能够裁切图片了，能够生成相应的路径数据了，再建立一个XML就可以保存数据在本地，然后再加一个读取显示的功能就完全OK了。没想到就这个建立XML的问题搞垮了我。
方法是这样的，我将一组xml里的信息的一部分读取下来，并重新构造，再将值放进了一个这样数组里，数组样式如下：“$readdata[]['aaa']＝值；$readdata[]['bbb']＝值；$readdata[]['ccc']＝值；”然后从网上搜罗了各种方法想去将这个数组转成xml，最终没能成功。
从网上搜罗一堆代码，没有哪种是类似的，而且非常让人恼火的是大部分都在重复着PHP5手册的例题，还大颜不惭的在那说是原创，天啊，喜悦国际村、CSDN，你们哪位里面有真实的东西可以帮我啊……
源代码如下：


$doc = new DOMDocument('1.0','utf-8');
$doc->formatOutput = true;
$root = $doc->createElement("root");
$doc->appendChild($root);
$items = $doc->createElement("item");
$root->appendChild($items);
foreach($readdata as $values) {
foreach($values as $key=>$val) {
$items->appendChild(new DOMElement($key,$val));
}
}
$doc->save("book1.xml");

想得到的结果如下：

<?xml version="1.0" encoding="utf-8"?>
<root>
<item>
<title>小伙伴</title>
<th_l_url>http://localhost/th_l_CIMG3627.jpg</th_l_url>
<th_l_filename>th_l_CIMG3627.jpg</th_l_filename>
<th_s_url>http://localhost/th_s_CIMG3627.jpg</th_s_url>
<th_s_filename>th_s_CIMG3627.jpg</th_s_filename>
<th_m_url>http://localhost/th_m_CIMG3627.jpg</th_m_url>
<th_m_filename>th_m_CIMG3627.jpg</th_m_filename>
<th_b_url>http://localhost/th_b_CIMG3627.jpg</th_b_url>
<th_b_filename>th_b_CIMG3627.jpg</th_b_filename>
</item>
<item>
<title>不许跑</title>
<th_l_url>http://localhost/th_l_CIMG5393.jpg</th_l_url>
<th_l_filename>th_l_CIMG5393.jpg</th_l_filename>
<th_s_url>http://localhost/th_s_CIMG5393.jpg</th_s_url>
<th_s_filename>th_s_CIMG5393.jpg</th_s_filename>
<th_m_url>http://localhost/th_m_CIMG5393.jpg</th_m_url>
<th_m_filename>th_m_CIMG5393.jpg</th_m_filename>
<th_b_url>http://localhost/th_b_CIMG5393.jpg</th_b_url>
<th_b_filename>th_b_CIMG5393.jpg</th_b_filename>
</item>
<item>
<title>笑一个</title>
<th_l_url>http://localhost/th_l_CIMG5413.jpg</th_l_url>
<th_l_filename>th_l_CIMG5413.jpg</th_l_filename>
<th_s_url>http://localhost/th_s_CIMG5413.jpg</th_s_url>
<th_s_filename>th_s_CIMG5413.jpg</th_s_filename>
<th_m_url>http://localhost/th_m_CIMG5413.jpg</th_m_url>
<th_m_filename>th_m_CIMG5413.jpg</th_m_filename>
<th_b_url>http://localhost/th_b_CIMG5413.jpg</th_b_url>
<th_b_filename>th_b_CIMG5413.jpg</th_b_filename>
</item>
</root>

实际得到的结果如下：

<?xml version="1.0" encoding="utf-8"?>
<root>
<item>
<title>小伙伴</title>
<th_l_url>http://localhost/th_l_CIMG3627.jpg</th_l_url>
<th_l_filename>th_l_CIMG3627.jpg</th_l_filename>
<th_s_url>http://localhost/th_s_CIMG3627.jpg</th_s_url>
<th_s_filename>th_s_CIMG3627.jpg</th_s_filename>
<th_m_url>http://localhost/th_m_CIMG3627.jpg</th_m_url>
<th_m_filename>th_m_CIMG3627.jpg</th_m_filename>
<th_b_url>http://localhost/th_b_CIMG3627.jpg</th_b_url>
<th_b_filename>th_b_CIMG3627.jpg</th_b_filename>
<title>不许跑</title>
<th_l_url>http://localhost/th_l_CIMG5393.jpg</th_l_url>
<th_l_filename>th_l_CIMG5393.jpg</th_l_filename>
<th_s_url>http://localhost/th_s_CIMG5393.jpg</th_s_url>
<th_s_filename>th_s_CIMG5393.jpg</th_s_filename>
<th_m_url>http://localhost/th_m_CIMG5393.jpg</th_m_url>
<th_m_filename>th_m_CIMG5393.jpg</th_m_filename>
<th_b_url>http://localhost/th_b_CIMG5393.jpg</th_b_url>
<th_b_filename>th_b_CIMG5393.jpg</th_b_filename>
<title>笑一个</title>
<th_l_url>http://localhost/th_l_CIMG5413.jpg</th_l_url>
<th_l_filename>th_l_CIMG5413.jpg</th_l_filename>
<th_s_url>http://localhost/th_s_CIMG5413.jpg</th_s_url>
<th_s_filename>th_s_CIMG5413.jpg</th_s_filename>
<th_m_url>http://localhost/th_m_CIMG5413.jpg</th_m_url>
<th_m_filename>th_m_CIMG5413.jpg</th_m_filename>
<th_b_url>http://localhost/th_b_CIMG5413.jpg</th_b_url>
<th_b_filename>th_b_CIMG5413.jpg</th_b_filename>
</item>
</root>


$items = $doc->createElement("item");
$root->appendChild($items);

如果将上面这两句移到第一层循环里，那么就产生如下结果：

<?xml version="1.0" encoding="utf-8"?>
<root>
<item>
<title>小伙伴</title>
</item>
<item>
<th_l_url>http://localhost/th_l_CIMG3627.jpg</th_l_url>
</item>
<item>
<th_l_filename>th_l_CIMG3627.jpg</th_l_filename>
</item>
<item>
<th_s_url>http://localhost/th_s_CIMG3627.jpg</th_s_url>
</item>
<item>
<th_s_filename>th_s_CIMG3627.jpg</th_s_filename>
........

肯定的说，我把循环或这个数组结构没搞清楚，或者我的方法根本就错了，拜托谁能帮帮忙啊……