Why xmlreader can't read something that xmlwriter wrote?

Question

I have the simplest code in the world,

using (XmlWriter writer = XmlWriter.Create(stringWriter))
{
 writer.WriteStartDocument();
 writer.WriteStartElement("Board");
 writer.WriteAttributeString("Rows", mRows.ToString());
 writer.WriteAttributeString("Columns", mColumns.ToString());
 writer.WriteEndElement();
 writer.WriteEndDocument();
}
TextWriter writer1 = new StreamWriter(path);
writer1.Write(stringWriter.toString());
writer1.Close();

Then i write it to a txt file that looks like this:

<?xml version="1.0" encoding="utf-16"?>
<Board Rows="30" Columns="50">
</Board>

Then i do the following :

FileStream str = new FileStream(s.FileName, FileMode.Open);
using(XmlReader reader = XmlReader.Create(stream))
{
reader.Read();
}

And it throws an exception :

"There is no Unicode byte order mark. Cannot switch to Unicode."

I googled the exception and found several workarounds, but i don't understand why i need a work around, i just want to read the xml i wrote. Can some one please explain what exactly the problem is ? Should i write something differently in the xml ?

What is the simplest solution to this ?

Answer 1

You're probably not writing to a unicode file which File.WriteAllText or a vanilla FileStream does not do.

Instead use File.OpenWrite or FileStream combined with the StreamWriter(Stream steam, Encoding encoding) constructor to specify unicode.

Sample:

var path = @"C:\Dev\sample.xml";

string xml;

var mRows = 30;
var mColumns = 50;

var options = new XmlWriterSettings { Indent = true };

using (var stringWriter = new StringWriter())
{
    using (var writer = XmlWriter.Create(stringWriter, options))
    {
        writer.WriteStartDocument();
        writer.WriteStartElement("Board");
        writer.WriteAttributeString("Rows", mRows.ToString());
        writer.WriteAttributeString("Columns", mColumns.ToString());
        writer.WriteEndElement();
        writer.WriteEndDocument();
    }
    xml = stringWriter.ToString();
}

if(File.Exists(path))
    File.Delete(path);

using(var stream = File.OpenWrite(path))
using(var writer = new StreamWriter(stream, Encoding.Unicode))
{
    writer.Write(xml);
}


Console.Write(xml);

using(var stream = File.OpenRead(path))
using(var reader = XmlReader.Create(stream))
{
    reader.Read();
}

File.Delete(path);