Add element to XML C#

Question

I´m trying to add the following element to a .XML on C#:

<Launch.Addon>
        <Name>IvAp</Name>
        <Disabled>False</Disabled>
        <Path>C:\Program Files (x86)</Path>
        <Commandline></Commandline>
</Launch.Addon>

With the following code:

XDocument xd1 = new XDocument();
xd1 = XDocument.Load(pathToAData + "\\dll.xml");

XElement root = new XElement("Launch Addon");
root.Add(new XElement("Name", "IvAp"));
root.Add(new XElement("Disable", "False"));
root.Add(new XElement("Path", "C:\\Program Files (x86)\\IVAO\\IvAp v2\\ivap_fsx_bootstrap.dll"));
root.Add(new XElement("Commandline"));
xd1.Element("Launch Addon").Add(root);
xd1.Save(pathToAData + "\\dll.xml");

But it throws an error in try {} catch {} block, I´ll be very thankful if you can help me

This is the error:

.System.Xml.XmlException: El carácter ' ', con valor hexadecimal 0x20, no puede incluirse en un nombre.

Based on the error message it must be the whitespace character in `new XElement("Launch Addon");` — balinta, Jun 11 '17 at 15:23
@CodingYoshi Still it doesnt work :(. I can´t make it work it writes something different than what I wanted — CTABUYO, Jun 11 '17 at 17:17

Maurice · Answer 1 · 2017-06-11T15:24:11.850

7

Although you didn't gave us the error, I assume that the whitespace here

new XElement("Launch Addon");

causes the error. Because whitespaces inside tag names are not allowed as far as I know. But check the specs for more information: https://www.w3.org/TR/REC-xml/#NT-NameChar

edited Jun 11 '17 at 15:24

answered Jun 11 '17 at 15:19

Maurice

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Also I am pretty sure this is a mistake as well xd1.Element("Launch Addon").Add(root); – Filip Cordas Jun 11 '17 at 15:22

score 1 · Accepted Answer · answered Jun 11 '17 at 18:28

You are almost there. First of all, as I mentioned in my comment, you need to remove the space from Launch Addon because XML element names cannot have a space.

Next, imagine this is your XML file:

<?xml version="1.0" encoding="utf-8"?>
<test>
    <addons>
    </addons>
</test>

Now you want to add something to it. You need to specify to which element you want to add the new element. So if you want to add an element to <test>, then you need to do this:

XElement root = new XElement("LaunchAddon");
root.Add(new XElement("Name", "IvAp"));
root.Add(new XElement("Disable", "False"));
root.Add(new XElement("Path", "C:\\Program Files (x86)\\IVAO\\IvAp v2\\ivap_fsx_bootstrap.dll"));
root.Add(new XElement("Commandline"));

xd1.Element("test").Add(root); //<-- See this, we are adding to test

If we wanted to add to <addons>, then we would do this:

xd1.Descendants("addons").First().Add(root);

Or you can use XPath to find the node to which you want to add the new node.

Add element to XML C#

2 Answers2