我是php和编码的新手。我正在尝试从远程设备解析xml并访问特定的值数据。我想显示组9探测器1值，例如我无法使其工作。有什么提示吗？
这是xml：
<?xml version="1.0" encoding="ISO-8859-1" ?>
- <Device id="S10011" hb="1935">
<Group id="1" />
<Group id="2" />
<Group id="3" />
<Group id="4" />
<Group id="5" />
<Group id="6" />
<Group id="7" />
<Group id="8" />
- <Group id="9">
- <Probe id="99">
<Value>1.0</Value>
</Probe>
- <Probe id="1">
<Value>86.4</Value>
</Probe>
- <Probe id="2">
<Value>45.7</Value>
</Probe>
- <Probe id="3">
<Value>2.9</Value>
</Probe>
- <Probe id="4">
<Value>1.0</Value>
</Probe>
</Group>
</Device>
这是我在xml中读取的php代码：
<?php
// Establish a port 80 connection
$http = fsockopen("192.168.2.106",80);
// Send a request to the server
$req = "GET /xmldata HTTP/1.0\r\n";
$req .= "Host: 192.168.2.106\r\n";
$req .= "Connection: Close\r\n\r\n";
fputs($http, $req);
// Output the request results
while(!feof($http)) {
$xmlstr .= fgets($http, 2048);
}
// Close the connection
fclose($http);
$xml = simplexml_load_string($xmlstr);
print_r($xml);
$myValue = $xml->xpath('//Group[@ID="9"]/Probe[@ID="1"]/value');
echo $myValue;
?>
print_r（$ xml）;显示以下信息：
SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => S10011
[hb] => 158221
)
[Group] => Array
(
[0] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 1
)
[0] =>
)
[1] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 2
)
[0] =>
)
[2] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 3
)
[0] =>
)
[3] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 4
)
[0] =>
)
[4] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 5
)
[0] =>
)
[5] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 6
)
[0] =>
)
[6] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 7
)
[0] =>
)
[7] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 8
)
[0] =>
)
[8] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 9
)
[Probe] => Array
(
[0] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 99
)
[Value] => 2.0
)
[1] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 1
)
[Value] => 89.6
)
[2] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 2
)
[Value] => 42.7
)
[3] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 3
)
[Value] => 3.9
)
[4] => SimpleXMLElement Object
(
[@attributes] => Array
(
[id] => 4
)
[Value] => 1.0
)
)
)
)
)
答案 0 :(得分：2)
请改为尝试：
$myValue = $xml->xpath('//Group[@id="9"]/Probe[@id="1"]/Value');
echo $myValue[0];
答案 1 :(得分：2)
您必须从HTTP响应中剥离HTTP标头，否则您将无法获得有效的XML文档。根据您的托管环境，您可以将HTTP URL传递给simplexml_load_file()，这比您正在进行的操作简单得多。
此外，您的xpath不起作用，因为XML属性和标记名称区分大小写。
$xml = simplexml_load_file("http://192.168.2.106/xmldata");
$myValue = $xml->xpath("//Group[@id='9']/Probe[@id='1']/Value");
echo $myValue[0];
XML源代码中的所有这些破折号都只是一个复制/粘贴问题吗？
答案 2 :(得分：0)
<?php
$device = getDoc();
// iterate over all Group elements that have one or more Probe elements that have one or more Value elements.
foreach( $device->xpath('Group[Probe/Value]') as $group ) {
echo 'Group id=', $group['id'], "\n";
foreach( $group->Probe as $probe ) {
echo ' probe id=', $probe['id'], "\n";
foreach( $probe->Value as $value ) {
echo ' value=', $value, "\n";
}
}
}
function getDoc() {
return new SimpleXMLElement('<?xml version="1.0" encoding="ISO-8859-1" ?>
<Device id="S10011" hb="1935">
<Group id="1" />
<Group id="2" />
<Group id="3" />
<Group id="4" />
<Group id="5" />
<Group id="6" />
<Group id="7" />
<Group id="8" />
<Group id="9">
<Probe id="99">
<Value>1.0</Value>
</Probe>
<Probe id="1">
<Value>86.4</Value>
</Probe>
<Probe id="2">
<Value>45.7</Value>
</Probe>
<Probe id="3">
<Value>2.9</Value>
</Probe>
<Probe id="4">
<Value>1.0</Value>
</Probe>
</Group>
</Device>');
}
打印
Group id=9
probe id=99
value=1.0
probe id=1
value=86.4
probe id=2
value=45.7
probe id=3
value=2.9
probe id=4
value=1.0
另请参阅：http://docs.php.net/simplexml.examples-basic和http://www.w3.org/TR/xpath/
答案 3 :(得分：0)
的xml：
<root><item attrname="5"/></root>
PHP：
$var = $xml->xpath('root/item/@attrname');
echo $var[0];
或＆gt; = php5.3
$var = $xml->xpath('root/item/@attrname')[0];
echo $var;
结果：
5