php中，怎么通过soap传递两个参数，（ms-security下）

php中，如何通过soap传递两个参数，（ms-security下）

<br />$xml = '<br />            <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"><br />            <wsse:UsernameToken><br />            <wsse:Username>admin</wsse:Username><br />            <wsse:Password>PasswordText</wsse:Password><br />            </wsse:UsernameToken><br />            </wsse:Security>';<br /><br />        $header = new SoapHeader('http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd', 'CallbackHandler', new SoapVar($xml, XSD_ANYXML), TRUE);<br /><br />        $this->client = new SoapClient($wsdl);<br />        $this->client->__setSoapHeaders(array($header));<br /><br />        $userInfo = turnObjectToArray($this->client->__call('checkUser', array('username' => array('username' => 'username', 'password' => 'password'))));<br /><br />

一运行上述代码，就提示出错

<br />SoapFault exception: [soap:Server] Fault occurred while processing. in <br />

后来连调时，对方看了下log，显示就把username传过去了，password没传过去


传递一个参数时对方是可以接收到的

<br />$info = turnObjectToArray($this->client->__call('getClasses', array('gradeId' => array('gradeId' => $data['id']))));<br />

怎么传递两个参数啊？？？
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注意大小写 ！