如何将字符串数组传递给PHP webservice

Question

How can i except an array of strings in PHP webservice.

<?php
require_once('lib/nusoap.php');
require_once ('dbinfomation.php');
$server = new soap_server();
$server->configureWSDL('processRecords', 'urn:processRecordswsdl');

$server->register('processRecords',       
    array('invoidId' => 'xsd:string', 'itemsIds'=>'xsd:Array'),        
    array('return' => 'xsd:string'),      
    'urn:processRecordswsdl',                      
    'urn:processRecordswsdl#processRecords',                
    'rpc',                                
    'encoded'
);
function processRecords($invoidId, array $params) {
        return 'Hello, ' . $invoidId;
}

$server->service(file_get_contents("php://input"));
?>

My method above should take two parameters one string (invoice Number) and the other one a list of string (items associated with this invoice)