比较并显示XML文件中的元素值。 [英] Compare and display the element value from XML file.

问题描述

我有一个与xml文件有关的问题。我可以在我的代码中读取一个xml文件，也可以提取轻元素及其值（我需要）。



但这显示了两个亮值。我需要显示一个值大于800的值。

xml如下：

hi , i have a problem related to xml file. i can read a xml file in my code and can also extract light element and its value as well (which i need).

but this show both light values. i need to display one having value greater than 800.
the xml is like :

<?xml version="1.0" encoding="utf-8"?>
<MotePacket>
  <ParsedDataElement>
    <Name>temp</Name>
    <ConvertedValue>21.981619</ConvertedValue>
  </ParsedDataElement>
  <ParsedDataElement>
    <Name>light</Name>
    <ConvertedValue>2037</ConvertedValue>
  </ParsedDataElement>
  <ParsedDataElement>
      <Name>temp</Name>
      <ConvertedValue>23.127808</ConvertedValue>
  </ParsedDataElement>
  <ParsedDataElement>
     <Name>light</Name>
     <ConvertedValue>128</ConvertedValue>
  </ParsedDataElement>
</MotePacket>

我的尝试：

What I have tried:

// READING NEW FILE 
            XmlTextReader Reader = new XmlTextReader(@"101.xml");
            XmlDocument doc = new XmlDocument();
            doc.Load(Reader);
            XPathNavigator nav = doc.CreateNavigator();

            //compile xpath 
            XPathExpression expr;
            expr = nav.Compile("/MotePacket/ParsedDataElement[Name='light']");
            XPathNodeIterator iterator = nav.Select(expr);

            //iterate node set and see values in list box
            listBox1.Items.Clear();
            try
            {
                while (iterator.MoveNext())
                {
                    XPathNavigator nav2 = iterator.Current.Clone();
                    listBox1.Items.Add("content and value: " + nav2);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }

推荐答案

答案已在SO板上提供： c＃ - 如果值增加阈值，则读取xml的特定元素 - Stack Overflow [ ^ ]

The answer has been provided on SO board: c# - reading perticular element of xml if value increase the threshold - Stack Overflow[^]

XDocument xdoc = XDocument.Load(fullfilename);

var data = xdoc.Descendants("ParsedDataElement")
    .Where(x=>x.Element("Name").Value == "light" && Double.Parse(x.Element("ConvertedValue").Value)>800)
    .Select(x=> new
    {
        Name =  x.Element("Name").Value,
        ConvertedValue = Double.Parse(x.Element("ConvertedValue").Value)
    })
    .ToList();

//load data into ListBox1 object
foreach(var item in data)
{
    ListBox1.Items.Add(item.ConvertedValue);
}

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