如何把DOMNode转换问题，弄了三天了，急~~

[jone_linux]

DOMNode放到DOMDocument里呢？
$clonenode = $nodes -> cloneNode(true);
$doc = new DOMDocument();
$newnode = $doc->appendChild($clonenode);
print $doc->saveXML();

Catchable fatal error: Argument 1 passed to DOMNode::appendChild() must be an instance of DOMNode, null given,
这样写不行，哪位知道该咋写呢？急！

[jone_linux]

重写下：
<NewDataSet>
<port order="07" sid="7">
<pyname>Ningbo</pyname>
<portname>NINGBO BRANCH</portname>
<add>Prime Center, NO.19 Hualou Lane, Haishu District, Ningbo</add>
<linkman>
</linkman>
<tel>86-5748584</tel>
<fax>86-574-68511</fax>
<msn>
</msn>
<email>[e-mail]</email>
<intro>
</intro>
</port>
</NewDataSet>

$xmldomxpath = new DOMXPath("上面那个文档");
$nodes = $xmldomxpath->query("/NewDataSet/port")->item(0);
$clonenode = $nodes -> cloneNode(true);

$doc = new DOMDocument("1.0");
$doc->formatOutput = true;
$doc->importNode($clonenode,true);
echo $doc->saveXML();
咋啥都不显示呢

[foolbirdflyfirst]

$dom   		 = new DOMDocument("1.0");
$dom->load("xml文件路径");
$xmldomxpath = new DOMXPath($dom);
$nodes = $xmldomxpath->query("/NewDataSet/port")->item(0);
$clonenode = $nodes -> cloneNode(true);

$doc = new DOMDocument("1.0");
$doc->formatOutput = true; 
$newNode = $doc->importNode($clonenode,true);
$doc->appendChild($newNode);
echo $doc->saveXML();