使用带有 C# 的 XmlDocument 读取 XML 数据 - 读取属性数据并拆分结果

Question

I'm trying to read some XML data using XmlDocument and having a few challenges.

My issues are as follows:

1. When I try to get the bfihost value, it gives me the bfihost , propwet and saar element values combined as a single output. Why is this and how do I get just the bfihost ?

2. Each Depth element has an attribute named duration . My first foreach loop writes the string durationString to the console, but it doesn't seem to find any attributes called duration in the XmlNode chldNode .

3. This issue is probably less important, but when I find the value for the element ReturnPeriods for example I can only retrieve all the values separated by commas. This isn't an issue as I've just used the Split(',') method and assigned it to an array and looped through that. I was curious if XmlDocument had a more elegant way of doing this?

Thanks for any help received.

Here is a stripped down version of the XML data. The , ... have been added as there is a lot more data in the actual xml file.

<?xml version="1.0" encoding="UTF-8" standalone="true"?>
<FEHCDROMExportedDescriptors appVersion="2.0.0.0" version="2.0.1">
    <PointDescriptors y="111111" x="222222" grid="GB">
        <bfihost>0.386</bfihost>
        <propwet>0.3</propwet>
        <saar>643</saar>
    </PointDescriptors>
    <PointDDF2013Values>
        <ReturnPeriods>
            <![CDATA[
                1.3, 1.58, 2, ...
            ]]>
        </ReturnPeriods>
        <Depths duration="0.083">
            <![CDATA[
                3.27693489525396, 3.98688804941076, 4.68688804941076, ...
            ]]>
        </Depths>
        <Depths duration="0.25">
            <![CDATA[
                5.37693489525396, 6.51484587430874, 7.81484587430874, ...
            ]]>
        </Depths>
        <Depths duration="0.5">
            <![CDATA[
                6.87693489525396, 8.38688804941076, 10.0017339237195, ...
            ]]>
        </Depths>
    </PointDDF2013Values>
</FEHCDROMExportedDescriptors>

The code I have written is as follows:

            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(file);

            XmlTextReader reader = new XmlTextReader(file);
            XmlNode node = xmlDoc.ReadNode(reader);

            string durationString;
            foreach (XmlNode chldNode in node.ChildNodes)
            {
                //Read the attribute duration
                if (chldNode.Name == "Depths")
                {
                    if (chldNode.HasChildNodes)
                    {
                        foreach (XmlNode item in node.ChildNodes)
                        {
                            durationString = chldNode.Attributes["duration"].Value;
                            Console.WriteLine("durations[]: " + durationString);

                        }
                    }
                }
            }


            XmlNodeList pointDescriptors = xmlDoc.GetElementsByTagName("PointDescriptors");
            XmlElement xmlElement = (XmlElement)pointDescriptors[0];

            // Get coordinates
            XmlAttribute y = xmlElement.GetAttributeNode("y");
            Console.WriteLine("y[]: " + y.InnerXml);
            XmlAttribute x = xmlElement.GetAttributeNode("x");
            Console.WriteLine("x[]: " + y.InnerXml);

            // for some reason returns the bfi Host, propwet and saar
            XmlNodeList bfihost = xmlDoc.GetElementsByTagName("bfihost");
            Console.WriteLine("bfihost[]: " + pointDescriptors[0].InnerText);

            // returns all return periods as a string.
            XmlNodeList returnPeriods = xmlDoc.GetElementsByTagName("ReturnPeriods");
            //Console.WriteLine("Return Periods[]: " + returnPeriods[0].InnerText);

            //I can split the string by commas and remove white spaces as follows
            string[] returnPeriodsArray = returnPeriods[0].InnerText.Split(',').Select(sValue => sValue.Trim()).ToArray();
            foreach (string s in returnPeriodsArray)
            {
                //System.Console.Write("{0} ", s);
            }

            int k = 0;
            //Loop through all the depths, and split the results
            XmlNodeList depths = xmlDoc.GetElementsByTagName("Depths");
            XmlAttribute duration;
            for (int i = 0; i < depths.Count; i++)
            {
                if (depths[i].InnerText.Length > 0)
                {
                    
                    System.Console.Write("{0} ", "\n\n" + "Depth xxx" + "\n\n");
                    string[] depthsArray = depths[i].InnerText.Split(',').Select(sValue => sValue.Trim()).ToArray();
                    foreach (string s in depthsArray)
                    {
                        System.Console.Write("{0} ", "(" + returnPeriodsArray[k] + ") - " + s + "\n");
                        k++;
                        if (k > 21)
                        {
                            k = 0;
                        }
                    }
                
                }
            }

And the output I get is:

y[]: 11111 //correct
x[]: 22222 //correct
bfihost[]: 0.3860.3643 //this is combination of three elements for some reason?

///Here I try to get the depth data but nothing is returned.

Depth xxx // xxx is just a place holder until I can fix the above issue.

 (1.3) - 3.27693489525396 //all these outputs are correct.
 (1.58) - 3.98688804941076
 (2) - 4.68688804941076


Depth xxx

 (1.3) - 5.37693489525396
 (1.58) - 6.51484587430874
 (2) - 7.81484587430874



Depth xxx

 (1.3) - 6.87693489525396
 (1.58) - 8.38688804941076
 (2) - 10.0017339237195

Answer 1

It is better to use LINQ to XML API. It is available in the.Net Framework since 2007.

c#

void Main()
{
    const string fileName = @"e:\Temp\FEHCDROME.xml";
    XDocument xdoc = XDocument.Load(fileName);
    
    XElement xelem = xdoc.Descendants("PointDescriptors").FirstOrDefault();

    Console.WriteLine("PointDescriptors:");
    Console.WriteLine("y[]: {0}", xelem.Attribute("y").Value);
    Console.WriteLine("x[]: {0}", xelem.Attribute("x").Value);
    Console.WriteLine("bfihost[]: {0}", xelem.Element("bfihost").Value);

    XElement rp = xdoc.Descendants("ReturnPeriods").FirstOrDefault();
    Console.WriteLine("{0}ReturnPeriods:", Environment.NewLine);
    foreach (string s in rp.Value.Split(',').Select(sValue => sValue.Trim()).ToArray())
    {
        Console.WriteLine("{0} ", s);
    }

    Console.WriteLine("{0}Depths:", Environment.NewLine);
    foreach (XElement dp in xdoc.Descendants("Depths"))
    {
        foreach (string s in dp.Value.Split(',').Select(sValue => sValue.Trim()).ToArray())
        {
            Console.WriteLine("{0} ", s);
        }
    }
}

Output

PointDescriptors:
y[]: 111111
x[]: 222222
bfihost[]: 0.386

ReturnPeriods:
1.3 
1.58 
2 
... 

Depths:
3.27693489525396 
3.98688804941076 
4.68688804941076 
... 
5.37693489525396 
6.51484587430874 
7.81484587430874 
... 
6.87693489525396 
8.38688804941076 
10.0017339237195 
...