add Xml in C#

[rull]

Example from MSDN: using System; using System.IO; using System.Xml; public class Sample { public static void Main() { XmlDocument doc = new XmlDocument(); doc.LoadXml("" + "Pride And Prejudice" + ""); XmlNode root = doc.DocumentElement; //Create a new node. XmlElement elem = doc.CreateElement("price"); elem.InnerText="19.95"; //Add the node to the document. root.AppendChild(elem); Console.WriteLine("Display the modified XML..."); doc.Save(Console.Out); } }

[Philip Fitzsimons]

you will need the System.Xml namespace and something like: string filename = "country.xml"; XmlDocument countryDocument = new XmlDocument(); countryDocument.Load(filename); XmlNode parisNode = countryDocument.SelectSingleNode("/Country/City[@Name = 'Paris']"); XmlNode newStreetNode = countryDocument.CreateNode("Street"); XmlAttribute newStreetNameAttr = countryDocument.CreateAttribute("Name"); newStreetNameAttr.Value = "my new street"; newStreetNode.Attributes.Append(newStreetAttr); XmlNode newStreetNameNode = countryDocument.CreateNode("Name"); newStreetNameNode.InnerText = " Test 4 "; newStreetNode.AppendChild(newStreetNameNode); XmlNode newStreetAgeNode = countryDocument.CreateNode("Age"); newStreetAgeNode.InnerText = " 42 "; newStreetNode.AppendChild(newStreetAgeNode); parisNode.AppendChild(newStreetNode); countryDocument.Save(filename);

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"When the only tool you have is a hammer, a sore thumb you will have."

[bertcox]

Thx a lot! But their is still a mistake i can't find. XmlNode parisNode = countryDocument.SelectSingleNode("/Country/City[@Name 'Paris']"); An unhandled exception of type 'System.Xml.XPath.XPathException' occurred in system.xml.dll Additional information: System error. Do you know what is wrong with the SelectSingleNode? Thx

[Philip Fitzsimons]

opps typo by me. mised the equals out! XmlNode parisNode = countryDocument.SelectSingleNode("/Country/City[@Name = 'Paris']");

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"When the only tool you have is a hammer, a sore thumb you will have."

[bertcox]

Sorry to disturb you again but there is another mistake :-) He puts this line in yellow : parisNode.AppendChild(newStreetNode); An unhandled exception of type 'System.NullReferenceException' occurred in CountryAddEdit.exe Additional information: Object reference not set to an instance of an object. And is it possible to put Paris in a string so if i want to change another city i just have to change the string? Thx!

[Philip Fitzsimons]

this is because the SelectSingleNode is failing. might be either your code or the xml file - can you post them. the SelectSingleNode use a plain string, so you can use what ever you want for it...

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"When the only tool you have is a hammer, a sore thumb you will have."

[bertcox]

string filename = @"c:\country.xml"; XmlDocument countryDocument = new XmlDocument(); countryDocument.Load(filename); XmlNode parisNode = countryDocument.SelectSingleNode("/Country/City[@Name = 'Paris']"); XmlNode newStreetNode = countryDocument.CreateNode(XmlNodeType.Element,"Street",null); XmlAttribute newStreetNameAttr = countryDocument.CreateAttribute("Name"); newStreetNameAttr.Value = "my new street"; newStreetNode.Attributes.Append(newStreetNameAttr); XmlNode newStreetNameNode = countryDocument.CreateNode(XmlNodeType.Element,"Name",null); newStreetNameNode.InnerText = " Test 4 "; newStreetNode.AppendChild(newStreetNameNode); XmlNode newStreetAgeNode = countryDocument.CreateNode(XmlNodeType.Element,"Age",null); newStreetAgeNode.InnerText = " 42 "; newStreetNode.AppendChild(newStreetAgeNode); parisNode.AppendChild(newStreetNode); countryDocument.Save(filename); countryDocument.CreateNode(XmlNodeType.Element,"Name",null); I found this in the MSDN because there was a mistake there to but did i fill it wrong?

[Philip Fitzsimons]

I should have just used CreateElement :) however, you can use CreateNode, but you don't need the null as we don't need an xml namespace. I suspect the problem is your xml file, can you post that up.

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"When the only tool you have is a hammer, a sore thumb you will have."

[bertcox]

This is the XML file (looks good in internet explorer) Test 24 Test2 19 Test3 33

[Philip Fitzsimons]

yes, I thought so, you have changed the case of "city" in your xml... so either change the SelectNode to be SelectSingleNode("/Country/city[@Name = 'Paris']"); or fix you xml to be "City".. rememeber XML is case sensitive, so its best to pick on style and stick to it..

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"When the only tool you have is a hammer, a sore thumb you will have."

[bertcox]

well done :-) the other problem: XmlNode newStreetNode = countryDocument.CreateNode(XmlNodeType.Element,"Street",null); I changed it into XmlNode newStreetNode = countryDocument.CreateNode(XmlNodeType.Element,"Street",""); Now it works :-D Thx!

[Philip Fitzsimons]

or you can use the short version: XmlNode newStreetNode = countryDocument.CreateElement("Street");

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"When the only tool you have is a hammer, a sore thumb you will have."

[bertcox]

off course :-D thx again