我正在解析一个 xml 文件。例如，当我输出一个属性时，我总是得到 2 次结果。

这是我所做的一些简化代码:

    $xml = new XMLReader();

    $xml->open($file);

    while ($xml->read()) {
        if ($xml->name == 'file')
            echo $xml->getAttribute ('Product_ID') . '<br />';
    }

    // close stream
    $xml->close();

这是我得到的:

1980 1980 37444 37444 45287 45287 65438 65438 76916 76916 101158 101158 271287 271287

XML 结构如下:

<file path="export/freexml.int/DE/15986140.xml" Product_ID="15986140" Updated="20121114141132" Quality="ICECAT" Supplier_id="728" Prod_ID="RBBD2MZ" Catid="2282" On_Market="0" Model_Name="ThinkCentre Edge 92z" Product_View="0" HighPic="http://images.icecat.biz/img/norm/high/15916192-2729.jpg" HighPicSize="12635" HighPicWidth="337" HighPicHeight="294" Date_Added="20121114000000"></file>
<file path="export/freexml.int/DE/15986142.xml" Product_ID="15986142" Updated="20121114143018" Quality="ICECAT" Supplier_id="24" Prod_ID="NX.C0ZEB.002" Catid="151" On_Market="0" Model_Name="TE11HC-32376G50Mnks" Product_View="0" HighPic="http://images.icecat.biz/img/norm/high/15986142-574.jpg" HighPicSize="179174" HighPicWidth="786" HighPicHeight="621" Date_Added="20121114000000"></file>
<file path="export/freexml.int/DE/15986149.xml" Product_ID="15986149" Updated="20121114144736" Quality="ICECAT" Supplier_id="24" Prod_ID="NX.C1UEB.001" Catid="151" On_Market="0" Model_Name="LE11-BZ-E1124G50Mn" Product_View="0" HighPic="http://images.icecat.biz/img/norm/high/15986149-2702.jpg" HighPicSize="205805" HighPicWidth="786" HighPicHeight="621" Date_Added="20121114000000"></file>
<file path="export/freexml.int/DE/15986153.xml" Product_ID="15986153" Updated="20121114200420" Quality="ICECAT" Supplier_id="1935" Prod_ID="50203" Catid="194" On_Market="0" Model_Name="Arma" Product_View="0" HighPic="http://images.icecat.biz/img/norm/high/15986153-3865.jpg" HighPicSize="1928713" HighPicWidth="2751" HighPicHeight="1897" Date_Added="20121114000000"></file>
<file path="export/freexml.int/DE/15986154.xml" Product_ID="15986154" Updated="20121114200048" Quality="ICECAT" Supplier_id="1935" Prod_ID="ARMAKB" Catid="194" On_Market="0" Model_Name="Arma" Product_View="0" HighPic="http://images.icecat.biz/img/norm/high/15986154-7619.jpg" HighPicSize="1928713" HighPicWidth="2751" HighPicHeight="1897" Date_Added="20121114000000"></file>
<file path="export/freexml.int/DE/15986155.xml" Product_ID="15986155" Updated="20121114194744" Quality="ICECAT" Supplier_id="1935" Prod_ID="ARMAM" Catid="195" On_Market="0" Model_Name="Arma" Product_View="0" HighPic="http://images.icecat.biz/img/norm/high/15986155-4238.jpg" HighPicSize="639005" HighPicWidth="2201" HighPicHeight="3265" Date_Added="20121114000000"></file>
<file path="export/freexml.int/DE/15986156.xml" Product_ID="15986156" Updated="20121114194735" Quality="ICECAT" Supplier_id="1935" Prod_ID="54577" Catid="195" On_Market="0" Model_Name="Arma" Product_View="0" HighPic="http://images.icecat.biz/img/norm/high/15986156-7292.jpg" HighPicSize="639005" HighPicWidth="2201" HighPicHeight="3265" Date_Added="20121114000000"></file>

如您所见，每个数字都显示两次。我不明白这个问题-.-.我做错了什么？

非常感谢你们的帮助!

//编辑

好的，我是这样修复的:

if ($xml->name == 'file' && $xml->nodeType == XMLReader::ELEMENT)

感谢您的帮助!

最佳答案

在文档的评论中找到这个:

might be obvious, but not to everyone ;-) ... when reading attributes from a node that has sub-nodes (and creating an output from this node), the output will be issued twice, once on the tag and once on the end tag . To avoid this, you can test on which part of the node you are using the property nodeType. It'll be 1 for the element, 15 for the end element.

http://www.php.net/manual/en/xmlreader.getattribute.php

您可以应用上述建议的解决方案，也可以使用另一种算法来遍历节点，如下所示: http://www.w3schools.com/php/php_xml_simplexml.asp

<?php
$xml = simplexml_load_file("test.xml");

echo $xml->getName() . "<br />";

foreach($xml->children() as $child)
  {
  echo $child->getName() . ": " . $child . "<br />";
  }
?>

更新 使用评论中提出的解决方案修改了您的代码。

$xml = new XMLReader();

$xml->open($file);

while ($xml->read()) {
    if ($xml->name == 'file' && $xml->nodeType==XMLReader::ELEMENT)
        echo $xml->getAttribute ('Product_ID') . '<br />';
}

// close stream
$xml->close();

关于PHP XMLReader 解析行 2 次，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13407430/