Problem with xmltextwriter Data at the root level is invalid. Line 1, position 1.

Jason

I am getting the error "Data at the root level is invalid. Line 1, position 1." when I try to load an xml file that I create. I know why the error is being thrown. The problem is the root node is not being written to the xml file correctly. I think I maybe doing something wrong but all of the examples I have looked at seems like I am creating the xml file right. Here is my code:

 

      //Check if the file exists so we do not override an existing file
      if (!File.Exists(fileName))
      {
        xmlTextWriter = new XmlTextWriter(fileName, null);

        //Add the root node to the document
        if (startNode != null)
        {
          xmlTextWriter.WriteStartDocument();
          xmlTextWriter.WriteStartElement(startNode);
          xmlTextWriter.WriteEndElement();
          xmlTextWriter.WriteEndDocument();
        }

        xmlTextWriter.Flush();
        xmlTextWriter.Close();
      }

Here is an example of what is created after the xmltextwriter is closed:

I am not sure why the root tag is being written like it is.
Thank you for any help!

5 Replies

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Tina Thomas16y ago
Accepted answer
I see, you used XmlDocument.LoadXml which accepts a string. So your file name is considered as the xml string and hence you see the error Data at the root level is invalid.
To solve your problem, use

xmlDocument.Load(fileName);

or

you can read the contents of the file and use xmlDocument.LoadXml

StreamReader sw = new StreamReader(fileName);
                string sXml= sw.ReadToEnd();
                XmlDocument oXDoc = new XmlDocument();
                oXDoc .LoadXml(sXml);
Tina Thomas16y ago
and mean the same thing.
If there are child nodes however, it has to be in the format

Hope it helps!
Jason16y ago
Thank you very much Tina!!! I used the load method and it worked out great. But I still don't understand why the WriteStartElement and WriteEndElement produces:

I would have thought that it would have created the following:

is the mean there are no elements in the root? Thanks again!!!
Jason16y ago
Yes I am trying to load using XMLDocument and that is where I get the error. When I use the WriteStartElement(node) and WriteEndElement() I was expecting to get something like this:

So from what you are saying, this:

is ok? I thought tags had to have a starting and ending tag. Also what kind of tag is ?
Here is my Code:
private XmlDocument xmlDocument;
private XmlTextWriter xmlTextWriter;
private string fileName;
public Serialize(string fileName, string startNode)
{
      this.fileName = fileName;
      xmlDocument = new XmlDocument();
      //Check if the file exists so we do not override an existing file
      if (!File.Exists(fileName))
      {
         xmlTextWriter = new XmlTextWriter(fileName, null);
                  //Add the root node to the document

         if (startNode != null)
        {

      xmlTextWriter.WriteStartDocument();
      xmlTextWriter.WriteStartElement(startNode);
      xmlTextWriter.WriteEndElement();
      xmlTextWriter.WriteEndDocument();
}
   xmlTextWriter.Flush();
   xmlTextWriter.Close();

}

   xmlDocument.LoadXml(fileName);
}
Tina Thomas16y ago
The XML that is generated is a perfectly formatted XML and there should no be problem with this XML. It is generated as expected from the code you have pasted. You haven't mentioned how you are trying to load it. Are you loading using XmlDocument?