XML

matthew king

Experts,

I am attempting to read the xml file below, but have become frustrated over the last 24-hrs with my inability to understand xpath and/or linq. Specifically, i'm attempting to abstract data based on user input. For example, if the user inputs"0024" into the "txtCarID" textbox and fires the click event, txtCarModel textbox would be populated with Chevy Camaro and txtOrig textbox would be populated with United States. Moreover, I need to populate the "cboxModel" combobox with all the Model ID associated with that particular car ID; so, if the user inputs "0024" into the "txtCarID" textbox, the "cboxModel" combobox would be populated with A01 and A03. Any help you could provide would be greatly appreciated as I'm trying to learn xml. Thank you!

Student

<>Chevy Camaro

United States

Michigan

Detroit

3.6

240000

5.7

31000

<>Chevy Cruz

United States

Michigan

Detroit

1.8

19000

1.8T

21500

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Accepted answer
Try the following LINQ to XML code:

using System;
using System.Xml.Linq;
using System.Linq;

// ...

private void button1_Click(object sender, EventArgs e)
{
string id = txtCarId.Text.Trim();

if (id == "")
{
MessageBox.Show("Please enter a car ID first");
txtCarId.Focus();
return;
}

XElement data = XElement.Load("student.xml"); // or whatever file path is
XElement selectedCar = (from car in data.Elements("CAR") where car.Attribute("id").Value == id select car).FirstOrDefault();
if (selectedCar != null)
{
txtCarModel.Text = selectedCar.Element("CarName").Value;
txtOrig.Text = selectedCar.Element("Country").Value;
cboxModel.Items.Clear();

foreach(XElement model in selectedCar.Elements("model"))
{
cboxModel.Items.Add(model.Attribute("id").Value);
}
}
else
{
MessageBox.Show("A car with the entered ID does not exist");
}
}

Note that there are some missing tags in the XML file (as posted). It should be:

<CarName>Chevy Camaro
United States
Michigan
Detroit

2
3.6
240000

2
5.7
31000

<CarName>Chevy Cruz
United States
Michigan
Detroit

4
1.8
19000

2
1.8T
21500
matthew king12y ago
You are awesome, Vulpes. Thanks for taking the time to type this out. I think I have a limited understanding now!