您可以使用我一直在研究的XMLParser。

$xml = XMLParser::encode(array(
    'bla' => 'blub',
    'foo' => 'bar',
    'another_array' => array (
        'stack' => 'overflow',
    )
));
// @$xml instanceof SimpleXMLElement
echo $xml->asXML();

会导致:

<?xml version="1.0"?>
<root>
    <bla>blub</bla>
    <foo>bar</foo>
    <another_array>
        <stack>overflow</stack>
    </another_array>
</root>

如果冗长的xml不成问题，可以使用xmlrpc_encode从数组创建xml。 www.php.net/xmlrpc_encode

注意，如果使用关联键和/或数字键，创建的XML会有所不同

<?php
// /params/param/value/struct/member
// there is a tag "member" for each element
// "member" contains a tag "name". its value is the associative key
$xml1 = xmlrpc_encode(array('a'=>'b','c'=>'d'));
$simplexml1 = simplexml_load_string($xml1);
print_r($xml1);
print_r($simplexml1);

// /params/param/value/array/data
// there is a tag "data" for each element
// "data" doesn't contain the tag "name"
$xml2 = xmlrpc_encode(array('a','b'));
$simplexml2 = simplexml_load_string($xml2);
print_r($xml2);
print_r($simplexml2);
?>

function toXML($data, $obj = false, $dom) {
    $is_first_level = false;
    if($obj === false) {
        $dom = new DomDocument('1.0');
        $obj = $dom;
        $is_first_level = true;
    }

    if(is_array($data)) {
        foreach($data as $key => $item) {
            $this->toXML($item, $obj->appendChild($dom->createElement($key)), $dom);
        }
    }else {
        $obj->appendChild($dom->createTextNode($data));
    }

    if($is_first_level) {
        $obj->formatOutput = true;
        return $obj->saveXML();
    }
    return $obj;
}

一个简短的例子:

<?php

$test_array = array (
  'bla' => 'blub',
  'foo' => 'bar',
  'another_array' => array (
    'stack' => 'overflow',
  ),
);
$xml = new SimpleXMLElement('<root/>');
array_walk_recursive($test_array, array ($xml, 'addChild'));
print $xml->asXML();

结果

<?xml version="1.0"?>
<root>
  <blub>bla</blub>
  <bar>foo</bar>
  <overflow>stack</overflow>
</root>

键和值会被交换——你可以在array_walk之前用array_flip()来修复这个问题。array_walk_recursive需要PHP 5。你可以用array_walk代替，但你不会得到'stack' => 'overflow'在XML中。

我发现这个解与原来的问题相似

<?php

$test_array = array (
  'bla' => 'blub',
  'foo' => 'bar',
  'another_array' => array (
    'stack' => 'overflow',
  ),
);

class NoSimpleXMLElement extends SimpleXMLElement {
 public function addChild($name,$value) {
  parent::addChild($value,$name);
 }
}
$xml = new NoSimpleXMLElement('<root/>');
array_walk_recursive($test_array, array ($xml, 'addChild'));
print $xml->asXML();

我的答案，拼凑别人的答案。这应该可以纠正无法补偿数字键的错误:

function array_to_xml($array, $root, $element) {
    $xml = new SimpleXMLElement("<{$root}/>");
    foreach ($array as $value) {
        $elem = $xml->addChild($element);
        xml_recurse_child($elem, $value);
    }
    return $xml;
}

function xml_recurse_child(&$node, $child) {
    foreach ($child as $key=>$value) {
        if(is_array($value)) {
            foreach ($value as $k => $v) {
                if(is_numeric($k)){
                    xml_recurse_child($node, array($key => $v));
                }
                else {
                    $subnode = $node->addChild($key);
                    xml_recurse_child($subnode, $value);
                }
            }
        }
        else {
            $node->addChild($key, $value);
        }
    }   
}

array_to_xml()函数假定数组首先由数字键组成。如果数组有一个初始元素，则可以从array_to_xml()函数中删除foreach()和$elem语句，只传递$xml。