How to search Textbox entered value in an xml file using C#

Question

I am a beginner in C#, Xml. If I have to enter a value (partnumber) in TextBox (say 704644-B21) , The partnumber should get searched in XML file, and display if it exists or not.

<Processor>
            <Item>
              <partnumber>678244-B21</partnumber>
              <processorname> E5-2637 Kit</processorname>
              <processortype>Dual Core</processortype>
              <quantity>2</quantity>
            </Item>
 </Processor>
 <Interconnects>
          <Interconnect Bay="Bay1" partnumber="516733-B21">Ethernet -  6120XG Blade Switch</Interconnect>
          <Interconnect Bay="Bay2" partnumber="641146-B21">Ethernet -  Fabric Ext Module</Interconnect>
          <Interconnect Bay="Bay3" partnumber="516733-B21">Ethernet - HP ProCurve 6120XG Blade Switch(516733-B21)</Interconnect>
          <Interconnect Bay="Bay4" partnumber="658250-B21">Ethernet - XG Blade Switch</Interconnect>
          <Interconnect Bay="Bay5" partnumber="658250-B21">Ethernet - XG Blade Switch</Interconnect>
          <Interconnect Bay="Bay6" partnumber="438031-B21">Ethernet - BL-c Switch</Interconnect>
          <Interconnect Bay="Bay7" partnumber="451438-B21">Ethernet - Cisco Catalyst Blade Switch 3120G</Interconnect>
          <Interconnect Bay="Bay8" partnumber="658250-B21">Ethernet - XG Blade Switch(658250-B21</Interconnect>
        </Interconnects>
</ModelDetails> 

When i input the part number in the text box, I want to know through Messagebox, if the part number entered in the textbox, exist in the xml file or not. If the Part number exists, Message box should display "Partnumber {0] exist" , else it must display," Part number {0} does not exist."

 private bool hasNode;
 XmlDocument xworkload = new XmlDocument();

private void btnPnoCheck_Click(object sender, RoutedEventArgs e)
        {            
            Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
            dlg.FileName = "Document";
            dlg.DefaultExt = ".hpa";
            dlg.Filter = "Xml document (.hpa)|*.hpa";

            var result = dlg.ShowDialog();
            if(result==true)
            {
                xworkload.Load(dlg.FileName);

                string xmlcontents = xworkload.InnerXml;

                string textToSearch = textBox1.Text;

                bool hasnode = (xworkload.DocumentElement.SelectNodes("//Item/partnumber[text()='" + textToSearch + "']").Count > 0) ;

                if (!hasnode)
                {
                    MessageBox.Show(String.Format("Part number {0}{1} found ", textBox1.Text, (!hasNode ? " not" : String.Empty)));
                }
                else
                    MessageBox.Show(String.Format("Part number {0} found" , textBox1.Text));               

            }

        }

The above code doesn't counts the partnumber inside 'Interconnects' tag

Answer 1

See SO question: Find an element in xml by its inner text

Search on an event (on a button click? On a textChanged? Depending on your needs) with a method like this:

// Load your document
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xmlFile);

string textToSearch = YourTextBox.Text;
bool hasNode = (xmlDoc.SelectNodes("/Expansion/ID[text()='" + textToSearch + "']").Count > 0);

Or

bool hasNode = (xmlDoc.SelectSingleNode("/Expansion/ID[text()='" + textToSearch + "']" != null);

EDIT: for your complement: if you want to display a message box only when the item if not found:

MessageBox.Show(String.Format("Item {0}{1} found", textBox1.Text, (!hasNode ? " not" : String.Empty)));

Answer 2

For an Instance use below in text changed event to identify the value entered. u could use the count of Val.

string xml = "";
XDocument doc = XDocument.Parse(xml);
string text = TextBox.Text;
var Val = doc.Descendants("Item").Where(txt => txt.Element("ID").Value.Equals(text));

Or the below returns the boolean value

var Val = doc.Descendants("Item").Where(txt => txt.Element("ID").Value.Equals(textbox)).Any();