Inserting XML into SQL Server without unicode issues

gistfile1.cs

using System.IO;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
...
using (SqlConnection connection = new SqlConnection("conn string"))
{
	connection.Open();
	string sql = "INSERT INTO mytable (xmlColumn) VALUES (@xmlData)";
	using (SqlCommand command = new SqlCommand(sql, connection))
	{
		// Swap round if the source file is unicode
		string xml = File.ReadAllText(@"C:\myxml.xml");		
		//string xml = File.ReadAllText(@"C:\myxml.xml", Encoding.Unicode);
		
		using (MemoryStream stream = new MemoryStream())
		{
			using (StreamWriter writer = new StreamWriter(stream, Encoding.Unicode))
			{
				writer.Write(xml);
				writer.Flush();
				stream.Position = 0;
				
				SqlParameter parameter = new SqlParameter("@xmlData", SqlDbType.Text);
				parameter.Value = new SqlXml(stream);
				command.Parameters.Add(parameter);
				command.ExecuteNonQuery();
			}
		}
	}
}