[英]Linq to XML - Get attribute and elements
Given this XML, how can I get data for each outageEvent including both attributes and elements?鉴于此 XML,我如何获取每个 outageEvent 的数据,包括属性和元素?
In the end, I need to move this data to a database, but doing this as a first step.最后,我需要将这些数据移动到数据库中,但这是第一步。
Desired end format is a 'row' for each outageEvent with the attribuite ObjectID and then the elements in outageEvent.所需的结束格式是每个带有属性 ObjectID 的 outageEvent 的“行”,然后是 outageEvent 中的元素。
outageEvent
-------------
ObjectID
Comment
objectName
...etc.
Not necessary to get grandchildren of outageEvent such as ExtensionList children at this point.此时不需要获取 outageEvent 的孙子节点,例如 ExtensionList 子节点。
So far I am working on querying with Linq to XML.到目前为止,我正在使用 Linq to XML 进行查询。 I'm able to query and get the objectIDs.
我能够查询并获取 objectID。 Separately, I am able to query to get all the elements.
另外,我可以查询以获取所有元素。 Trying to combine the two is giving me problems.
试图将两者结合起来给我带来了问题。 Haven't done any C# in a while, so that is 99% of the problem.
有一段时间没有做任何 C#,所以这是 99% 的问题。
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Header>
</soap:Header>
<soap:Body>
<OutageEventChangedNotification xmlns="http://www.multispeak.org/Version_4.1_Release">
<oEvents>
<outageEvent objectID="2021-10-16-0002">
<comments>Test outage 2</comments>
<extensionsList>
<extensionsItem>
<extName>primaryCrew</extName>
<extValue>Primary Crew Name</extValue>
<extType>string</extType>
</extensionsItem>
</extensionsList>
<objectName>Outage Name</objectName>
<!-- more elements -->
</outageEvent>
<outageEvent objectID="2021-10-16-0001">
<comments>Test outage 1</comments>
<!-- more elements -->
</outageEvent>
</oEvents>
</OutageEventChangedNotification>
</soap:Body>
</soap:Envelope>
C# code: C#代码:
XElement outages = XElement.Parse(requestBody);
XNamespace oecn = "http://www.multispeak.org/Version_4.1_Release";
//This works
IEnumerable<string> outageIDs = from outage in outages.Descendants(oecn + "outageEvent")
select (string) outage.Attribute("objectID");
foreach (string outageID in outageIDs)
{
Console.WriteLine($"IENUMBERABLE: {outageID}");
}
//This works
IEnumerable<string> outageProperties = from outage in outages.Descendants(oecn + "outageEvent")
select (string)outage;
foreach (string outageProperty in outageProperties)
{
Console.WriteLine($"IENUMBERABLE: {outageProperty} \r\n");
}
//This Doesn't
var alloutages = from outage in outages.Descendants(oecn + "outageEvent")
select new /*Error Here*/
{
outageID = outage.Attribute("objectID").Value,
comments = outage.Element("comments").Value
};
foreach (var outage in alloutages)
{
Console.WriteLine($"OUTPUT: {outage.outageID}");
}
Output:输出:
Hello World!
IENUMBERABLE: 2021-10-16-0002
IENUMBERABLE: 2021-10-16-0001
IENUMBERABLE: Test outage 2primaryCrewPrimary Crew NamestringOutage Name0032.427326-99.788595TRANSFORMER1District9TRANSFORMER1TransformerA10FeederNameAssumed2015-01-01T10:00:00Z2015-01-01T10:30:00Z2015-01-01T11:00:00ZCrew1Crew21010Contractor44
IENUMBERABLE: Test outage 1primaryCrewPrimary Crew NamestringOutage Name0032.427326-99.788595TRANSFORMER1District9TRANSFORMER1TransformerA10FeederNameAssumed2015-01-01T10:00:00Z2015-01-01T10:30:00Z2015-01-01T11:00:00ZCrew11010Contractor44
Error at var = alloutages section, highlighting the 'select new' block. var = alloutages 部分出错,突出显示“选择新”块。
System.NullReferenceException
HResult=0x80004003
Message=Object reference not set to an instance of an object.
Source=ParseXMLWithLinq
StackTrace:
at XMLParse.Program.<>c.<Main>b__0_2(XElement outage) in
System.Xml.Linq.XContainer.Element(...) returned null.
Contents of alloutages looks like this: alloutages 的内容如下所示:
<outageEvent objectID="2021-10-16-0002" xmlns="http://www.multispeak.org/Version_4.1_Release">
<comments>Test outage 2</comments>
<extensionsList>
<extensionsItem>
<extName>primaryCrew</extName>
<extValue>Primary Crew Name</extValue>
<extType>string</extType>
...
</outageEvent>
The reason for exception is comments
element inside outageEvent
is in the same namespace as outageEvent
, so in http://www.multispeak.org/Version_4.1_Release
.之所以例外是
comments
元素里面outageEvent
是在同一个命名空间outageEvent
,所以在http://www.multispeak.org/Version_4.1_Release
。 So instead of:所以而不是:
select new /*Error Here*/
{
outageID = outage.Attribute("objectID").Value,
comments = outage.Element("comments").Value
};
You need to do:你需要做:
select new /*Error Here*/
{
outageID = outage.Attribute("objectID").Value,
// use namespace you already have here
comments = outage.Element(oecn + "comments").Value
};
Alternative approach is to filter elements by local name:另一种方法是按本地名称过滤元素:
select new /*Error Here*/
{
outageID = outage.Attribute("objectID").Value,
comments = outage.Elements().First(c => c.Name.LocalName == "comments").Value
};
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