Deserializing of a XML string as a object does not work with .NET 1.1 SP1 anymore

[Chrigel]

Hi all,

We have problems deseralizing objects previously serialized as XML.
This did work fine with .NET 1.1 but since we have installed SP1,
deserializing fails (but serializing works). The error occurs within
the following line "return formatter.Deserialize(xmlReader) as
ParameterList;" and the "innerexception" sais "The root element is
missing.".

Thanks for any hints

Chrigel

Here is the code:
--------------

using System;
using System.Windows.Forms;
using System.IO;
using System.Xml.Serialization;

namespace ConsoleApplication1
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
try
{
ParameterList l = new ParameterList();
string s = l.SerializeToString();
l = null;
l = ParameterList.Deserialize(s);
s = "";
}
catch(Exception e)
{
MessageBox.Show(e.Message);
}
}
}

[Serializable]
[XmlType("ParameterList1")]
public class ParameterList
{
public string a = "";
public ParameterList()
{
a = "hugo";
}

public static ParameterList Deserialize(string sVesselData)
{
MemoryStream stream = new MemoryStream();
byte[] bytes = System.Text.Encoding.UTF8.GetBytes(sVesselData);
stream.Write(bytes,0,bytes.Length);
XmlSerializer formatter = new XmlSerializer(typeof(ParameterList));
System.Xml.XmlTextReader xmlReader = new
System.Xml.XmlTextReader(stream);
stream.Seek(0,0);
return formatter.Deserialize(xmlReader) as ParameterList;
}

public string SerializeToString()
{
System.IO.MemoryStream stream = new System.IO.MemoryStream();
System.Xml.Serialization.XmlSerializer formatter = new
XmlSerializer(typeof(ParameterList));
System.Xml.XmlTextWriter xmlWriter = new
System.Xml.XmlTextWriter(stream,System.Text.Encodi ng.UTF8);
xmlWriter.Flush();
stream.Seek(0,0);
formatter.Serialize(xmlWriter, this);
return System.Text.Encoding.UTF8.GetString(stream.GetBuff er());
}
}
}

[Tom Dacon]

I haven't done any recent serialization/deserialization myself, but one
program I wrote some time ago (in the VS.2002 days) did, and I noticed then
that the XML file created by the serialization process wasn't well-formed
XML. In fact there was no root element, which is exactly what your
deserialization error is reporting. Perhaps SP1 changes the rules in some
way.

Tom Dacon
Dacon Software Consulting

"Chrigel" <ch*****************@hotmail.com> wrote in message
news:c7**************************@posting.google.c om...

Hi all,

We have problems deseralizing objects previously serialized as XML.
This did work fine with .NET 1.1 but since we have installed SP1,
deserializing fails (but serializing works). The error occurs within
the following line "return formatter.Deserialize(xmlReader) as
ParameterList;" and the "innerexception" sais "The root element is
missing.".

Thanks for any hints

Chrigel

Here is the code:
--------------

using System;
using System.Windows.Forms;
using System.IO;
using System.Xml.Serialization;

namespace ConsoleApplication1
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
try
{
ParameterList l = new ParameterList();
string s = l.SerializeToString();
l = null;
l = ParameterList.Deserialize(s);
s = "";
}
catch(Exception e)
{
MessageBox.Show(e.Message);
}
}
}

[Serializable]
[XmlType("ParameterList1")]
public class ParameterList
{
public string a = "";
public ParameterList()
{
a = "hugo";
}

public static ParameterList Deserialize(string sVesselData)
{
MemoryStream stream = new MemoryStream();
byte[] bytes = System.Text.Encoding.UTF8.GetBytes(sVesselData);
stream.Write(bytes,0,bytes.Length);
XmlSerializer formatter = new XmlSerializer(typeof(ParameterList));
System.Xml.XmlTextReader xmlReader = new
System.Xml.XmlTextReader(stream);
stream.Seek(0,0);
return formatter.Deserialize(xmlReader) as ParameterList;
}

public string SerializeToString()
{
System.IO.MemoryStream stream = new System.IO.MemoryStream();
System.Xml.Serialization.XmlSerializer formatter = new
XmlSerializer(typeof(ParameterList));
System.Xml.XmlTextWriter xmlWriter = new
System.Xml.XmlTextWriter(stream,System.Text.Encodi ng.UTF8);
xmlWriter.Flush();
stream.Seek(0,0);
formatter.Serialize(xmlWriter, this);
return System.Text.Encoding.UTF8.GetString(stream.GetBuff er());
}
}
}

[Chrigel]

Hi all,

Thanks to Pascal (pag) who sent me the following link:

http://www.dotnettalk.net/showthread.php?t=262

Microsoft made the following change to XmlTextReader:

1) In the constructor of XmlTextReader, they read 4kB from the stream you
pass in.
2) The constructor blocks until it gets a full 4k
3) Every time you call XmlTextReader.Read(), if there isn't enough data in
the internal buffer, it reads a full 4k. And *blocks* until it gets a full
4k.

They wanted to fix another issue but it seems this has created
another problem. The workaround is to read the contents of the stream into
some buffer such as a MemoryStream then pass that to the XmlTextReader.

So I changed the my Deserialize(..) method as follows:

public static ParameterList Deserialize(string sVesselData)
{
MemoryStream stream = new MemoryStream();
byte[] bytes = System.Text.Encoding.UTF8.GetBytes(sVesselData);
stream.Write(bytes,0,bytes.Length);
XmlSerializer formatter = new XmlSerializer(typeof(ParameterList));
System.Xml.XmlTextReader xmlReader = new System.Xml.XmlTextReader(stream);
stream.Seek(0,0);

StreamReader t_reader = new StreamReader(stream);
string mystring = t_reader.ReadToEnd();
xmlReader = new System.Xml.XmlTextReader(new StringReader(mystring));

return formatter.Deserialize(xmlReader) as ParameterList;
}

And this works with or without SP1!

Regards, Chrigel

[Tom Dacon]

Yikes!

TD

"Chrigel" <ch*****************@hotmail.com> wrote in message
news:c7*************************@posting.google.co m...

Hi all,

Thanks to Pascal (pag) who sent me the following link:

http://www.dotnettalk.net/showthread.php?t=262

Microsoft made the following change to XmlTextReader:

1) In the constructor of XmlTextReader, they read 4kB from the stream you
pass in.
2) The constructor blocks until it gets a full 4k
3) Every time you call XmlTextReader.Read(), if there isn't enough data in
the internal buffer, it reads a full 4k. And *blocks* until it gets a full
4k.

They wanted to fix another issue but it seems this has created
another problem. The workaround is to read the contents of the stream into
some buffer such as a MemoryStream then pass that to the XmlTextReader.

So I changed the my Deserialize(..) method as follows:

public static ParameterList Deserialize(string sVesselData)
{
MemoryStream stream = new MemoryStream();
byte[] bytes = System.Text.Encoding.UTF8.GetBytes(sVesselData);
stream.Write(bytes,0,bytes.Length);
XmlSerializer formatter = new XmlSerializer(typeof(ParameterList));
System.Xml.XmlTextReader xmlReader = new
System.Xml.XmlTextReader(stream);
stream.Seek(0,0);

StreamReader t_reader = new StreamReader(stream);
string mystring = t_reader.ReadToEnd();
xmlReader = new System.Xml.XmlTextReader(new StringReader(mystring));

return formatter.Deserialize(xmlReader) as ParameterList;
}

And this works with or without SP1!

Regards, Chrigel