PHP中SimpleXMLElement对象字符编码

<?xml version="1.0" encoding="gbk" ?>

$strXml = ‘<?xml version="1.0" encoding="gbk" ?>
    <SnsPropSet></SnsPropSet>‘;                 
$objXml = simplexml_load_string($strXml);       
$objXml->addAttribute(‘SnsCID‘, $this->intCid); 
$objXml->addAttribute(‘SnsTID‘, $this->intTid); 
$objXml->addAttribute(‘SnsPID‘, $this->intPid); 
                                                
$intCount = $strCount = 0;                      
if (is_int($mixSnsAttrVal)) {                   
    $objXmlChild = $objXml->addChild(‘PropInt‘);
    $intCount++;                                
} else {                                        
    $objXmlChild = $objXml->addChild(‘PropDyn‘);
    $strCount++;                                
}                                               
                                                
$objXmlChild->addAttribute(‘ID‘, $intSnsAttrId);
$objXmlChild->addAttribute(‘V‘, $mixSnsAttrVal);
$objXml->addAttribute(‘PropIntC‘, $intCount);   
$objXml->addAttribute(‘PropDynC‘, $strCount);   
                                                
$strXml = $objXml->asXML();