Article ID: 888226 - Last Review: December 3, 2007 - Revision: 1.2

You receive an unhandled exception error message when you use the MemoryStream class in the .NET Framework 1.1 Service Pack 1

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SYMPTOMS

When you try to use the MemoryStream class to read a memory stream in a Microsoft Visual C# .NET 2003 project, you may receive an error message that is similar to one of the following:

Unhandled Exception: System.Xml.XmlException: The root element is missing.

Unhandled Exception: System.IO.SomeStreamException: The memory stream is at the end of the buffer.

Unhandled Exception: System.IO.SomeReaderException: The reader cannot read anymore.

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CAUSE

This behavior occurs if the following conditions are true:

You install the Microsoft .NET Framework 1.1 Service Pack 1 (SP1).
The memory stream is positioned at the end-of-stream.

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WORKAROUND

To work around this behavior, reset the stream position before you create the XmlTextReader class. For an example, see the "More Information" section.

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MORE INFORMATION

Steps to reproduce the behavior

Create a text file that is named Output.txt, and then paste the following code in Output.txt:

<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Body><HelloWorldResponse xmlns="http://tempuri.org/">
<HelloWorldResult>SUCCESS:test</HelloWorldResult></HelloWorldResponse></soap:Body></soap:Envelope>

In Visual C# .NET, create a new Console Application project. By default, Class1.cs is created.

Paste the following code in the Class1.cs file:

using System;
using System.IO;
using System.Text;
using System.Xml;

public class Form1
{
	static void Main() 
	{
		try
		{

			Stream _oldStream = new FileStream(@"Output.txt", FileMode.Open, FileAccess.Read);
			Stream _newStream = new MemoryStream();

			TextReader tr = new StreamReader(_oldStream);
			TextWriter tw = new StreamWriter(_newStream);
			tw.WriteLine(tr.ReadToEnd());
			tw.Flush();

			XmlReader reader = new XmlTextReader( new StreamReader( _newStream ) );
			_newStream.Position = 0;
			_newStream.Seek( 0, SeekOrigin.Begin );
			reader.Read();

			while( reader.Read() );

			Console.WriteLine("Success");
		}
		catch (Exception ex)
		{
			System.Diagnostics.Debug.WriteLine(ex.ToString());
			Console.WriteLine("Exception : " + ex.Message + "\n" + ex.StackTrace);
		}
	}
}