Question

I have a XML file template like this that comes from some IC chips, I want to be able to store each Pins Test type datas as an array so later I can draw it on a cartesian graph.

The data structure is like this:
<NUMBER></NUMBER> is name of the IC’s particular pin
<Curve Count=""> is number of tests done to a pin
<Type></Type> is type of test

and there are some voltage values and current values that I have to put in an array so I can use it later.

Anyway! My question is how can I get these values? I do not ask for a direct answer (but it is appriciated) but some guide that make me to find the thread is really appriciated.

EDIT: If somone kindly give me a code to have 3 voltage and 3 current values from A1 I can easily get the idea and continue myself.

This XML looks likes this:

<?xml version="1.0" encoding="utf-8"?>
<Document>
  <Device>NEC555</Device>
  <Pins Count="3">
    <Pin>
      <Number>A1</Number>
      <Curves Count ="3">
        <Curve>
          <Type>PreStress</Type>
          <VIPairs Count="3">
            <VIPair>
              <Voltage>-2</Voltage>
              <Current>-0.003</Current>
            </VIPair>
            <VIPair>
              <Voltage>-1</Voltage>
              <Current>-0.002</Current>
            </VIPair>
            <VIPair>
              <Voltage>-0</Voltage>
              <Current>-0.001</Current>
            </VIPair>
          </VIPairs>
        </Curve>
        <Curve>
          <Type>PreFail</Type>
          <VIPairs Count="3">
            <VIPair>
              <Voltage>-2</Voltage>
              <Current>-0.003</Current>
            </VIPair>
            <VIPair>
              <Voltage>-1</Voltage>
              <Current>-0.002</Current>
            </VIPair>
            <VIPair>
              <Voltage>-0</Voltage>
              <Current>-0.001</Current>
            </VIPair>
          </VIPairs>
        </Curve>
        <Curve>
          <Type>PostFail</Type>
          <VIPairs Count="0">
          </VIPairs>
        </Curve>
      </Curves>
    </Pin>
    <Pin>
      <Number>B1</Number>
      <Curves Count ="3">
        <Curve>
          <Type>PreStress</Type>
          <VIPairs Count="3">
            <VIPair>
              <Voltage>-3</Voltage>
              <Current>-0.005</Current>
            </VIPair>
            <VIPair>
              <Voltage>-1</Voltage>
              <Current>-0.002</Current>
            </VIPair>
            <VIPair>
              <Voltage>-0</Voltage>
              <Current>-0.001</Current>
            </VIPair>
          </VIPairs>
        </Curve>
        <Curve>
          <Type>PreFail</Type>
          <VIPairs Count="3">
            <VIPair>
              <Voltage>-3</Voltage>
              <Current>-0.003</Current>
            </VIPair>
            <VIPair>
              <Voltage>-1</Voltage>
              <Current>-0.002</Current>
            </VIPair>
            <VIPair>
              <Voltage>-0</Voltage>
              <Current>-0.001</Current>
            </VIPair>
          </VIPairs>
        </Curve>
        <Curve>
          <Type>PostFail</Type>
          <VIPairs Count="0">
          </VIPairs>
        </Curve>
      </Curves>
    </Pin>
  </Pins>
</Document>

Answer 1

Much as I like using LINQ and XDocument, this is a case where XPath is simpler.

Given your XML, this XPath finds all of the VIPair elements under a Pin element with a given Number and under a Curve element with a given Type:

/Document/Device/Pins/Pin[Number='A1']/Curves/Curve[Type='PreStress']/VIPairs/VIPair

Using an XmlDocument, the code to get your three voltage and current values would look like this:

string number = "A1";
string type = "PreStress"
string xpath = string.Format(
   "/Document/Device/Pins/Pin[Number='{0}']/Curves/Curve[Type='{1}']/VIPairs/VIPair",
   number,
   type);
foreach (XmlElement viPair in doc.SelectNodes(xpath))
{
   string current = viPair.SelectSingleNode("Current").Value;
   string voltage = viPair.SelectSingleNode("Voltage").Value;
}

Using an XDocument, the code would be:

var values = doc.XPathSelectElements(xpath)
   .Select(x => new { Voltage = x.Element("Voltage").Value(),
                      Current = x.Element("Current").Value() });

Unless your document’s been previously validated against a schema, you may want to make the last node test in the XPath VIPair[Current and Voltage], so that the code doesn’t fail if there’s a VIPair element that’s missing one of those child elements. (Alternatively, you might actually want the code to throw an exception if that happens; it really depends on the quality of the source data.)