XElement 上的 XPath 列表
List of XPaths on XElement
我试图在我的 C# 中获取第一个 xpath 匹配的值 -
private string getValue(List<string> xpaths, XElement xml) {
string stringValue = string.Empty;
foreach(string xpath in xPaths)
{
var value = xml.XPathEvaluate(xpath);
if (value is IEnumerable)
{
foreach (XObject xObject in value)
{
if (xObject is XElement)
{
stringValue = ((XElement)xObject).Value.FirstOrDefault().ToString();
break;
}
else if (xObject is XAttribute)
{
stringValue = ((XAttribute)xObject).Value.FirstOrDefault().ToString();
break;
}
}
}
else
stringValue = value.ToString();
}
return stringValue;
}
我的列表将如下所示 -
//Request/Header/Error/text()
//Request/Header/Error[0]/Details/ErrorMesage/text()
//Request/Header/Error/Details/@code
//Request/Header/Error/Details/StackTrace/text()
在 XPaths 列表中,我想遍历列表和 return 第一个匹配项。 XPathEvaluate 对我不起作用。我不确定哪里出了问题。
可能的 XML 个值
<Request>
<Header>
<Error>
<Details>
<StackTrace>trace</StackTrace>
</Details>
<Error>
</Header>
</Request>
<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message1.</ErrorMessage>
</Details>
<Error>
<Error>
<Details>
<ErrorMessage>This is the Error Message2.</ErrorMessage>
</Details>
<Error>
</Header>
</Request>
<Request>
<Header>
<Error>This is the error message.<Error>
</Header>
</Request>
<Request>
<Header>
<Error>
<Details code="123">
<StackTrace>trace</StackTrace>
</Details>
<Error>
</Header>
</Request>
<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message.</ErrorMessage>
</Details>
<Error>
</Header>
</Request>
这是传递给这样的方法-
getValue(xpathList, XElement.Parse(xmlString))
因为我不知道 xml 我会得到什么,所以我想循环浏览 XPath 列表和 return 第一个匹配项。它可以是元素文本或属性值。
首先,我们使用XDocument
,你可以使用XElement
但你需要将XPath表达式更改为xpathList
,
more details:
1 - 您在所有 xml
测试用例中都存在错误,Error
标签未关闭,然后更正它们:
<Request>
<Header>
<Error>
<Details>
<StackTrace>trace</StackTrace>
</Details>
</Error>
</Header>
</Request>
2 - 你在这个表达式 //Request/Header/Error[0]/Details/ErrorMesage/text()
中有错误,
要获得第一个 Error
使用 1
而不是 0
,你也会错过 s
in ErrorMesage
:
List<string> xPathList = new List<string>
{
"//Request/Header/Error/text()",
"//Request/Header/Error[1]/Details/ErrorMessage/text()",
"//Request/Header/Error/Details/@code",
"//Request/Header/Error/Details/StackTrace/text()"
};
3 - 改变GetValue
,像下面的代码:
private string GetValue(List<string> xPaths, XDocument xml)
{
string stringValue = string.Empty;
foreach (string xpath in xPaths)
{
var value = xml.XPathEvaluate(xpath);
foreach (XObject xObject in (IEnumerable)value)
{
if (xObject is XElement)
{
return ((XElement)xObject).Value;
}
else if (xObject is XAttribute)
{
return ((XAttribute)xObject).Value;
}
else
{
return ((XText)xObject).Value;
}
}
}
return stringValue;
}
4 - 测试
string result = GetValue(xPathList, XDocument.Parse(xmlString));
5 - 演示:
string xml1 = @"<Request>
<Header>
<Error>
<Details>
<StackTrace>trace</StackTrace>
</Details>
</Error>
</Header>
</Request>";
string xml2 = @"<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message1.</ErrorMessage>
</Details>
</Error>
<Error>
<Details>
<ErrorMessage>This is the Error Message2.</ErrorMessage>
</Details>
</Error>
</Header>
</Request>";
string xml3 = @"<Request>
<Header>
<Error>This is the error message.</Error>
</Header>
</Request>";
string xml4 = @"<Request>
<Header>
<Error>
<Details code=""123"">
<StackTrace>trace</StackTrace>
</Details>
</Error>
</Header>
</Request>";
string xml5 = @"<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message.</ErrorMessage>
</Details>
</Error>
</Header>
</Request>";
List<string> xPathList = new List<string>
{
"//Request/Header/Error/text()",
"//Request/Header/Error[1]/Details/ErrorMessage/text()",
"//Request/Header/Error/Details/@code",
"//Request/Header/Error/Details/StackTrace/text()"
};
string result1 = GetValue(xPathList, XDocument.Parse(xml1));
Console.WriteLine($"xml1 : {result1}");
string result2 = GetValue(xPathList, XDocument.Parse(xml2));
Console.WriteLine($"xml2 : {result2}");
string result3 = GetValue(xPathList, XDocument.Parse(xml3));
Console.WriteLine($"xml3 : {result3}");
string result4 = GetValue(xPathList, XDocument.Parse(xml4));
Console.WriteLine($"xml4 : {result4}");
string result5 = GetValue(xPathList, XDocument.Parse(xml5));
Console.WriteLine($"xml5 : {result5}");
6 - 结果
xml1 : trace
xml2 : This is the Error Message1.
xml3 : This is the error message.
xml4 : 123
xml5 : This is the Error Message.
希望对您有所帮助
我试图在我的 C# 中获取第一个 xpath 匹配的值 -
private string getValue(List<string> xpaths, XElement xml) {
string stringValue = string.Empty;
foreach(string xpath in xPaths)
{
var value = xml.XPathEvaluate(xpath);
if (value is IEnumerable)
{
foreach (XObject xObject in value)
{
if (xObject is XElement)
{
stringValue = ((XElement)xObject).Value.FirstOrDefault().ToString();
break;
}
else if (xObject is XAttribute)
{
stringValue = ((XAttribute)xObject).Value.FirstOrDefault().ToString();
break;
}
}
}
else
stringValue = value.ToString();
}
return stringValue;
}
我的列表将如下所示 -
//Request/Header/Error/text()
//Request/Header/Error[0]/Details/ErrorMesage/text()
//Request/Header/Error/Details/@code
//Request/Header/Error/Details/StackTrace/text()
在 XPaths 列表中,我想遍历列表和 return 第一个匹配项。 XPathEvaluate 对我不起作用。我不确定哪里出了问题。
可能的 XML 个值
<Request>
<Header>
<Error>
<Details>
<StackTrace>trace</StackTrace>
</Details>
<Error>
</Header>
</Request>
<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message1.</ErrorMessage>
</Details>
<Error>
<Error>
<Details>
<ErrorMessage>This is the Error Message2.</ErrorMessage>
</Details>
<Error>
</Header>
</Request>
<Request>
<Header>
<Error>This is the error message.<Error>
</Header>
</Request>
<Request>
<Header>
<Error>
<Details code="123">
<StackTrace>trace</StackTrace>
</Details>
<Error>
</Header>
</Request>
<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message.</ErrorMessage>
</Details>
<Error>
</Header>
</Request>
这是传递给这样的方法-
getValue(xpathList, XElement.Parse(xmlString))
因为我不知道 xml 我会得到什么,所以我想循环浏览 XPath 列表和 return 第一个匹配项。它可以是元素文本或属性值。
首先,我们使用XDocument
,你可以使用XElement
但你需要将XPath表达式更改为xpathList
,
more details:
1 - 您在所有 xml
测试用例中都存在错误,Error
标签未关闭,然后更正它们:
<Request>
<Header>
<Error>
<Details>
<StackTrace>trace</StackTrace>
</Details>
</Error>
</Header>
</Request>
2 - 你在这个表达式 //Request/Header/Error[0]/Details/ErrorMesage/text()
中有错误,
要获得第一个 Error
使用 1
而不是 0
,你也会错过 s
in ErrorMesage
:
List<string> xPathList = new List<string>
{
"//Request/Header/Error/text()",
"//Request/Header/Error[1]/Details/ErrorMessage/text()",
"//Request/Header/Error/Details/@code",
"//Request/Header/Error/Details/StackTrace/text()"
};
3 - 改变GetValue
,像下面的代码:
private string GetValue(List<string> xPaths, XDocument xml)
{
string stringValue = string.Empty;
foreach (string xpath in xPaths)
{
var value = xml.XPathEvaluate(xpath);
foreach (XObject xObject in (IEnumerable)value)
{
if (xObject is XElement)
{
return ((XElement)xObject).Value;
}
else if (xObject is XAttribute)
{
return ((XAttribute)xObject).Value;
}
else
{
return ((XText)xObject).Value;
}
}
}
return stringValue;
}
4 - 测试
string result = GetValue(xPathList, XDocument.Parse(xmlString));
5 - 演示:
string xml1 = @"<Request>
<Header>
<Error>
<Details>
<StackTrace>trace</StackTrace>
</Details>
</Error>
</Header>
</Request>";
string xml2 = @"<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message1.</ErrorMessage>
</Details>
</Error>
<Error>
<Details>
<ErrorMessage>This is the Error Message2.</ErrorMessage>
</Details>
</Error>
</Header>
</Request>";
string xml3 = @"<Request>
<Header>
<Error>This is the error message.</Error>
</Header>
</Request>";
string xml4 = @"<Request>
<Header>
<Error>
<Details code=""123"">
<StackTrace>trace</StackTrace>
</Details>
</Error>
</Header>
</Request>";
string xml5 = @"<Request>
<Header>
<Error>
<Details>
<ErrorMessage>This is the Error Message.</ErrorMessage>
</Details>
</Error>
</Header>
</Request>";
List<string> xPathList = new List<string>
{
"//Request/Header/Error/text()",
"//Request/Header/Error[1]/Details/ErrorMessage/text()",
"//Request/Header/Error/Details/@code",
"//Request/Header/Error/Details/StackTrace/text()"
};
string result1 = GetValue(xPathList, XDocument.Parse(xml1));
Console.WriteLine($"xml1 : {result1}");
string result2 = GetValue(xPathList, XDocument.Parse(xml2));
Console.WriteLine($"xml2 : {result2}");
string result3 = GetValue(xPathList, XDocument.Parse(xml3));
Console.WriteLine($"xml3 : {result3}");
string result4 = GetValue(xPathList, XDocument.Parse(xml4));
Console.WriteLine($"xml4 : {result4}");
string result5 = GetValue(xPathList, XDocument.Parse(xml5));
Console.WriteLine($"xml5 : {result5}");
6 - 结果
xml1 : trace
xml2 : This is the Error Message1.
xml3 : This is the error message.
xml4 : 123
xml5 : This is the Error Message.
希望对您有所帮助