C# XML解析检查属性是否存在
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XML parse check if attribute exist
提问by Joe
I've made a method which checks if an attribute exist in a XML-file. If it does not exist it returns "False". It works but it takes a very long time to parse the file. It seems it reads the whole file for each single row. Have I missed something here? Can I make it more effective somehow?
我已经创建了一个方法来检查一个属性是否存在于 XML 文件中。如果它不存在，则返回“False”。它可以工作，但解析文件需要很长时间。它似乎为每一行读取整个文件。我在这里错过了什么吗？我可以以某种方式使其更有效吗？
public static IEnumerable<RowData> getXML(string XMLpath)
{
XDocument xmlDoc = XDocument.Load("spec.xml");
var specs = from spec in xmlDoc.Descendants("spec")
select new RowData
{
number= (string)spec.Attribute("nbr"),
name= (string)spec.Attribute("name").Value,
code = (string)spec.Attribute("code").Value,
descr = (string)spec.Attribute("descr").Value,
countObject = checkXMLcount(spec),
return specs;
}
public static string checkXMLcount(XElement x)
{
Console.WriteLine(x.Attribute("nbr").Value);
Console.ReadLine();
try
{
if (x.Attribute("mep_count").Value == null)
{
return "False";
}
else
{
return x.Attribute("mep_count").Value;
}
}
catch
{
return "False";
}
}
I tested to replace the method with one that only returns and receive string:
我测试用一个只返回和接收字符串的方法替换该方法：
public static string checkXMLcount(string x)
{
Console.WriteLine(x);
Console.ReadLine();
return x;
}
I made a XML-file with only one single row. The console prints out the value 15 times. Any ideas?
我制作了一个只有一行的 XML 文件。控制台打印出该值 15 次。有任何想法吗？
采纳答案by Joe
Solved! No extra method needed:
解决了！不需要额外的方法：
countObject = spec.Attribute("mep_count") != null ? spec.Attribute("mep_count").Value : "False",
回答by Prabhu Murthy
You can try this and see if there is any improvement
你可以试试这个，看看是否有任何改进
class xmlAttributes
{
public string Node;
public Dictionary<string, string> Attributes;
}
Now with this LINQ,all attributes are stored in a dictionary(per Node) and could be accessed through the attribute name.
现在有了这个 LINQ，所有属性都存储在字典中（每个节点），可以通过属性名称访问。
var Result = XElement.Load("somedata.xml").Descendants("spec")
.Select(x => new xmlAttributes
{
Node = x.Name.LocalName,
Attributes = x.Attributes()
.ToDictionary(i => i.Name.LocalName,
j => j.Value)
});
Checks if an attribute exists on all XML Nodes
检查属性是否存在于所有 XML 节点上
var AttributeFound = Result.All(x => x.Attributes.ContainsKey("AttrName"));
Checks if the attribute appears at least once
检查属性是否至少出现一次
var AttributeFound = Result.Any(x => x.Attributes.ContainsKey("AttrName"));
