FormatException, converting a string to a long

Question

I was getting values from an XML file and placing them inside a dataGridView. I was successful in doing so, but after I want to manipulate data that I got from an XML file, It does not work and i get an error of Input string was not in a correct format. .

My goal is to convert a data captured from an XML File and divide it by 1024. Ain't InnerText a string that I can safely convert to a long? should I add more code to make this work?

During my debugging, i printed out the value of temp and the Value is 53999759360, I also tried not making it ToString() , same error

Here is part of my code: (The value of size is "53999759360")

        XmlDocument doc = new XmlDocument();
        string xmlFilePath = @"C:\xampp\htdocs\userInfo.xml";
        doc.Load(xmlFilePath);

        XmlNodeList accountList = doc.GetElementsByTagName("account");

        foreach (XmlNode node in accountList)
        {
            XmlElement accountElement = (XmlElement)node;

            foreach (XmlElement dskInterface in node.SelectNodes("systemInfo/dskInfo/dskInterface"))
            {
                String temp = (dskInterface["size"].InnerText).ToString();
                long iasdas = Convert.ToInt64(temp) / 1024; // Error Happens here
            }
        }

Answer 1

I'm afraid that your code works fine. It must be that the "temp" variable is string.Empty or whitespace.

I created an XmlDocument (from XDocument, sorry. I think it's a lot easier to work with) that looks like what you're targeting and ran your code. It runs fine and gives a proper value:

var xDoc = new XDocument(
            new XDeclaration("1.0", "UTF-8", "no"),
            new XElement("root",
                new XElement("account",
                    new XElement("systemInfo",
                        new XElement("dskInfo",
                            new XElement("dskInterface",
                                new XElement("size", 53999759360)))))));

var doc = new XmlDocument();
using (var xmlReader = xDoc.CreateReader())
{
    doc.Load(xmlReader);
}


XmlNodeList accountList = doc.GetElementsByTagName("account");

foreach (XmlNode node in accountList)
{
    XmlElement accountElement = (XmlElement)node;

    foreach (XmlElement dskInterface in node.SelectNodes("systemInfo/dskInfo/dskInterface"))
    {
        String temp = (dskInterface["size"].InnerText).ToString();
        long iasdas = Convert.ToInt64(temp) / 1024; // Error Happens here
    }
}

Edit: Here's an easier way to test what's actually happening:

Convert.ToInt64(null); // Doesn't crash
Convert.ToInt64(string.Empty); // Crashes
Convert.ToInt64(""); // Will crash if you comment the line above
Convert.ToInt64(" "); // Will crash if you comment the lines above