Check sum total on an element

April 19, 2022

I am trying to get the checksum total of an XML file as seen below:

<?xml version="1.0"?>

<student_update date="2022-04-19" program="CA" checksum="20021682">
    <transaction>
        <program>CA</program>
        <student_no>10010823</student_no>
        <course_no>*</course_no>
        <registration_no>216</registration_no>
        <type>2</type>
        <grade>90.4</grade>
        <notes>Update Grade Test</notes>
    </transaction>
    <transaction>
        <program>CA</program>
        <student_no>10010859</student_no>
        <course_no>M-50032</course_no>
        <registration_no>*</registration_no>
        <type>1</type>
        <grade>*</grade>
        <notes>Register Course Test</notes>
    </transaction>
</student_update>

I am wondering if I am going about this the right way.. please let me know:

XDocument xDocument = XDocument.Load(inputFileName);
XElement root = xDocument.Element("student_update");
IEnumerable<XElement> studentnoElement = xDocument.Descendants().Where(x => x.Name == "student_no");
int checksum = studentnoElement.Sum(x => Int32.Parse(x.Value));
if (!root.Attribute("checksum").Value.Equals(checksum))
{
  throw new Exception(String.Format("Incorrect checksum total " + "for file {0}\n", inputFileName));
}

I am running into some errors with the exception not popping up as expected, I am looking for some advice on how to correct this. Thank you!

>Solution :

From the root element of the checksum attribute, you are getting the value with the string type.

You can check with:

Console.WriteLine(root.Attribute("checksum").Value.GetType());

You have to convert to Integer first before comparing both values.

int rootCheckSum = Convert.ToInt32(root.Attribute("checksum").Value);
if (!rootCheckSum.Equals(checksum))
{
    throw new Exception(String.Format("Incorrect checksum total " + "for file {0}\n", inputFileName));
}

Or prefer safely convert to Integer with Int32.TryParse()

int rootCheckSum = Convert.ToInt32(root.Attribute("checksum").Value);
bool isInteger = Int32.TryParse(root.Attribute("checksum").Value, out int rootCheckSum);
if (!isInteger)
{
    // Handle non-integer case
}

if (!rootCheckSum.Equals(checksum))
{
    throw new Exception(String.Format("Incorrect checksum total " + "for file {0}\n", inputFileName));
}

Sample Program