XML and C# - WriteEndElement

Question

I'm using System.Xml to create an XML document in C#

My question is hopefully a simple one, do I need to use the WriteEndElement to close an XML tag?

For example, I have found that the following code will compile with or without 'writer.WriteEndElement();' and produce the same XML either way, however if I put 'writer.WriteEndElement();' twice, the program throws an exception.

writer.WriteStartElement("CustomerNo");
writer.WriteString("12345");
writer.WriteEndElement();

I'm not lazy and don't mind putting this in where it needs to be if this is how it's supposed to be, I just need some guidance here.

Thanks

John

Without a call to WriteEndElement how would writer know that the new WriteStartElement is a nested element or a sibling? — Muhammad Hasan Khan
– Muhammad Hasan Khan, Commented Sep 28, 2011 at 18:52
As already answered: Yes. Have you already consider XmlDocument and XDocument? An XmlWriter is only needed to crreate very large files. — Henk Holterman
– Henk Holterman, Commented Sep 28, 2011 at 18:58

score 6 · Accepted Answer · 2011-09-29 11:40:36Z

6

Generally speaking: Yes, for each WriteStartElement() there must be a matching WriteEndElement().

Think of the containment hierarchy as a stack - the Starts ("pushes") and Ends ("pops") must balance. If you try to "pop" beyond the end, it's a failure and an exception is thrown, like you describe.

As an example, to write a B element within the A element:

WriteStartElement("A");
WriteStartElement("B");
// ... attributes or content added here will become part af B element
WriteEndElement(); // Closes the open B element.
WriteEndElement(); // Closes the open A element.

Update: As @Sam points out in another answer, when - as in the example you give - you want to only write out simple content elements (no attributes or child elements), you may want to take a look at the convenience method WriteElementString(), which automatically wraps the content in start/end tags.

Hope this helps.

edited Sep 29, 2011 at 11:40

answered Sep 28, 2011 at 18:53

user116587

Sign up to request clarification or add additional context in comments.

Comments

Colonel Panic · Accepted Answer · 2013-04-05 15:19:20Z

3

Somewhere, there's a call to XmlWriter.Close, which—among other things—makes sure

Any elements or attributes left open are automatically closed.

If you didn't call XmlWriter.Close explicitly, C# will do so itself (via XmlWriter.Dispose after the object goes out of scope)

edited Apr 5, 2013 at 15:19

answered Apr 4, 2013 at 16:18

Colonel Panic

138k98 gold badges420 silver badges483 bronze badges

2 Comments

JMK Over a year ago

Thanks for the response, however this was about two years ago and I have since moved jobs, and figured it out! Cheers

GrzegorzM Over a year ago

Really don't understand why the author didn't up-voted it. IMO, you are the only one who really answered the original question. +1 from me.

Sam · Accepted Answer · 2011-09-28 20:45:50Z

2

I agree with Cumbayah's answer, however you can alternatively use XmlTextWriter's WriteElementString(string,string) method if you just want an element with a value inside (no attributes, no child elements).

Example:

writer.WriteElementString("CustomerNo", "12345");

I highly recommend this as it will save a lot of space and make the code more readable.

Also, to really go the extra mile you could do:

writer.WriteElementString(XmlConvert.EncodeName("CustomerNo"), "12345");

Encode and Decode XML Element and Attribute Names and ID Values

The XmlTextWriter class does not perform character checks by default. For example, the code WriteElementString("Order Detail", "My order"), produces an invalid element of My order.

To encode the element value, the correct encoding is writer.WriteElementString(XmlConvert.EncodeName("Order Detail"), "My order") which produces the valid element My order.

answered Sep 28, 2011 at 20:45

Sam

27.4k12 gold badges78 silver badges103 bronze badges

2 Comments

user116587 Over a year ago

+1 for mentioning the convenience method for writing simple-content elements. Updating my reply to include reference.

Sam Over a year ago

@Cumbayah Thanks. I gave you +1 as well since I agree with your answer - and I want that cool sportsmanship badge. ;)

Mark Kram · Accepted Answer · 2011-09-28 21:08:54Z

I use XDoument to create my XM Files, here is what I use to create an XML FIle:

XDocument doc = new XDocument(
                    new XDeclaration("1.0", "utf-8", "yes"),
                        new XComment(" "),
                        new XComment("My Company, Inc"),
                        new XComment("Comment XML File\n"),
                        new XComment("Don't edit this file with first consulting with Me."),
                        new XComment(" "),
                        new XComment(" "),
                        new XElement("Main1",
                            new XElement("Application",
                                new XElement("RemoteServer", "127.0.0.1"),
                                new XElement("AppVersion", "1.00.0000"),"
                                new XElement("UpdateNecessary", "No")
                                ),
                        new XElement("Departments",
                            new XElement("Item", "Sales"),
                                new XElement("Item", "Shipping"),
                                new XElement("Item", "Human Resources"),
                                new XElement("Item", "Technical Support")
                                )
                                ));

oberfreak · Accepted Answer · 2011-09-28 21:22:11Z

0

I would suggest using XMLSerialization in C# to first create a ObjectModel, which can be filled easily, and afterwards you can just save it down to XML.
Just Tag your ObjectModel Serializable and use Datatype which can be serialized or Implement ISerializable to do so.
Any Problems with different stylings, or even structural changes can be handled smooth via the ObjectModel. And the XMLSerializer is doing the job for you.
If you can't use an ObjectModel, i would suggest using an XmlDocument
To Create the Nodes. Here you can also use NamespaceTables and as far as i know, you can't create corrupt XML Files.

answered Sep 28, 2011 at 21:22

oberfreak

1,81515 silver badges20 bronze badges

Comments

Deepak Jha · Accepted Answer · 2019-06-05 12:55:40Z

0

Response.Clear();
Response.ContentType = "application/rss+xml";
XmlTextWriter writer = new XmlTextWriter(@"E:\product.xml", 
System.Text.Encoding.UTF8);

writer.WriteStartDocument(true);
writer.WriteStartElement("rss");
writer.WriteAttributeString("version", "2.0");
writer.WriteStartElement("produts");

writer.Formatting = Formatting.Indented;
writer.Indentation = 2; 

createNode("1", "Product 1", "1000", writer);
createNode("2", "Product 2", "2000", writer);
createNode("3", "Product 3", "3000", writer);
createNode("4", "Product 4", "4000", writer);

writer.WriteEndElement();
writer.WriteEndElement();
writer.Close();

answered Jun 5, 2019 at 12:55

Deepak Jha

3794 silver badges10 bronze badges

Collectives™ on Stack Overflow

XML and C# - WriteEndElement

6 Answers 6

Comments

2 Comments

2 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

6 Answers 6

Comments

2 Comments

2 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related