其他解决方案:

$marray=array(....);
$options = array(
                "encoding" => "UTF-8",
                "output_type" => "xml", 
                "version" => "simple",
                "escaping" => array("non-ascii, on-print, markup")
                );
$xmlres = xmlrpc_encode_request('root', $marray, $options);
print($xmlres);

我发现所有的答案都是使用过多的代码。这里有一个简单的方法:

function to_xml(SimpleXMLElement $object, array $data)
{   
    foreach ($data as $key => $value) {
        if (is_array($value)) {
            $new_object = $object->addChild($key);
            to_xml($new_object, $value);
        } else {
            // if the key is an integer, it needs text with it to actually work.
            if ($key != 0 && $key == (int) $key) {
                $key = "key_$key";
            }

            $object->addChild($key, $value);
        }   
    }   
}   

然后，将数组发送到使用递归的函数中就很简单了，因此它将处理多维数组:

$xml = new SimpleXMLElement('<rootTag/>');
to_xml($xml, $my_array);

现在$xml包含了一个漂亮的xml对象，它完全基于您编写数组的方式。

print $xml->asXML();

下面讨论名称空间。在本例中，构造包装器以包含名称空间定义，并将其传递给函数。使用冒号来标识命名空间。

测试数组

$inarray = [];
$inarray['p:apple'] = "red";
$inarray['p:pear'] = "green";
$inarray['p:peach'] = "orange";
$inarray['p1:grocers'] = ['p1:local' => "cheap", 'p1:imported' => "expensive"];


$xml = new SimpleXMLElement( '<p:wrapper xmlns:p="http://namespace.org/api" xmlns:p1="http://namespace.org/api2 /> ');

array_to_xml($xml,$inarray); 




function array_to_xml(SimpleXMLElement $object, array $data)
{   
    $nslist = $object->getDocNamespaces();

    foreach ($data as $key => $value)
    {   
        $nspace = null;
        $keyparts = explode(":",$key,2);
        if ( count($keyparts)==2) 
            $nspace = $nslist[$keyparts[0]];

        if (is_array($value))
        {   
            $key = is_numeric($key) ? "item$key" : $key;
            $new_object = $object->addChild($key,null,$nspace);
            array_to_xml($new_object, $value);
        }   
        else
        {   
            $key = is_numeric($key) ? "item$key" : $key;
            $object->addChild($key, $value,$nspace);
        }   
    }   
}   

只是对上面的函数进行了编辑，当键是数字时，添加前缀“key_”

// initializing or creating array
$student_info = array(your array data);

// creating object of SimpleXMLElement
$xml_student_info = new SimpleXMLElement("<?xml version=\"1.0\"?><student_info></student_info>");

// function call to convert array to xml
array_to_xml($student,$xml_student_info);

//saving generated xml file
$xml_student_info->asXML('file path and name');


function array_to_xml($student_info, &$xml_student_info) {
     foreach($student_info as $key => $value) {
          if(is_array($value)) {
            if(!is_numeric($key)){
                $subnode = $xml_student_info->addChild("$key");
                array_to_xml($value, $subnode);
            }
            else{
                $subnode = $xml_student_info->addChild("key_$key");
                array_to_xml($value, $subnode);
            }
          }
          else {
               if(!is_numeric($key)){
                    $xml_student_info->addChild("$key","$value");
               }else{
                    $xml_student_info->addChild("key_$key","$value");
               }
          }
     }
}

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();

总之……我使用了onokazu的代码(谢谢!)，并添加了在XML中重复标记的能力，它还支持属性，希望有人发现它有用!

 <?php

function array_to_xml(array $arr, SimpleXMLElement $xml) {
        foreach ($arr as $k => $v) {

            $attrArr = array();
            $kArray = explode(' ',$k);
            $tag = array_shift($kArray);

            if (count($kArray) > 0) {
                foreach($kArray as $attrValue) {
                    $attrArr[] = explode('=',$attrValue);                   
                }
            }

            if (is_array($v)) {
                if (is_numeric($k)) {
                    array_to_xml($v, $xml);
                } else {
                    $child = $xml->addChild($tag);
                    if (isset($attrArr)) {
                        foreach($attrArr as $attrArrV) {
                            $child->addAttribute($attrArrV[0],$attrArrV[1]);
                        }
                    }                   
                    array_to_xml($v, $child);
                }
            } else {
                $child = $xml->addChild($tag, $v);
                if (isset($attrArr)) {
                    foreach($attrArr as $attrArrV) {
                        $child->addAttribute($attrArrV[0],$attrArrV[1]);
                    }
                }
            }               
        }

        return $xml;
    }

        $test_array = array (
          'bla' => 'blub',
          'foo' => 'bar',
          'another_array' => array (
            array('stack' => 'overflow'),
            array('stack' => 'overflow'),
            array('stack' => 'overflow'),
          ),
          'foo attribute1=value1 attribute2=value2' => 'bar',
        );  

        $xml = array_to_xml($test_array, new SimpleXMLElement('<root/>'))->asXML();

        echo "$xml\n";
        $dom = new DOMDocument;
        $dom->preserveWhiteSpace = FALSE;
        $dom->loadXML($xml);
        $dom->formatOutput = TRUE;
        echo $dom->saveXml();
    ?>