Apparent bug in XmlSerializer or XmlTextWriter or something

[Integer Software]

Hi.

I have a really simple set of classes that writes 2 pathnames to a xml
file. I can write the default ok. Then if I change 1 pathname to a
shorter one, then rewrite the xml file, the remains of the old pathname,
and closing tags are left on the end resulting in an invalid XML file.
XmlSerializer.Deserialize gives a System.InvalidOperationException with
additional information: Error in the XML document.

My default file for example looks like: (sorry about the wrapping if its
wrapped)

ÿþ<?xml version="1.0" encoding="utf-16"?><settings
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><InstallDir>G:\Visual
Studio Projects\Initio2_take2\bin\Debug</InstallDir><DataDir>G:\Visual
Studio Projects\Initio2_take2\bin\Debug</DataDir></settings>

After shortening the DataDir path, and rewriting the Xml file, it looks
like this:

ÿþ<?xml version="1.0" encoding="utf-16"?><settings
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><InstallDir>G:\Visual
Studio
Projects\Initio2_take2\bin\Debug</InstallDir><DataDir>\\Linux\public\temp</DataDir></settings>bin\Debug</DataDir></settings>

See at the end, the "bin\Debug</DataDir></settings>" bit at the end
should not be there.

Heres my relevant code: Writing section:

public void writeOutConfigStore()
{
try
{
IsolatedStorageFile isoStore =
IsolatedStorageFile.GetStore(IsolatedStorageScope.User |
IsolatedStorageScope.Assembly, null, null);
IsolatedStorageFileStream target =
new
IsolatedStorageFileStream("Initio",
FileMode.OpenOrCreate,
FileAccess.Write,
FileShare.Write,
10240,
isoStore);
XmlSerializer serializer =
new
XmlSerializer(typeof(settings));
XmlWriter writer =
new XmlTextWriter(target,
Encoding.Unicode);
// Serialize using the XmlTextWriter.
serializer.Serialize(writer, ourSettings);
writer.Close();
target.Close();
isoStore.Close();
modified = false; }
catch(Exception e)
{
MessageBox.Show(e.Message);
}
}
My reading section:
public config()
{
//
// TODO: Add constructor logic here
//
ourSettings = new settings();

// Check for per user Isolated Storage
try
{
IsolatedStorageFile isoStore =
IsolatedStorageFile.GetStore(IsolatedStorageScope.User |
IsolatedStorageScope.Assembly, null, null);

IsolatedStorageFileStream isoStream =
new IsolatedStorageFileStream(
"Initio",
FileMode.Open,
FileAccess.Read,
FileShare.Read,
isoStore);
XmlSerializer serializer = new XmlSerializer(typeof(settings));
XmlReader reader = new
XmlTextReader(isoStream); // This should probably be a xml reader or
something
ourSettings = (settings)
serializer.Deserialize(reader);
// Read the data.

reader.Close();
isoStream.Close();
isoStore.Close();
modified = false;
return;
}
catch(System.IO.FileNotFoundException)
{
// This means first time user, and
needs to build a default settings file.
MessageBox.Show("New User");
createNewConfigStore();
return;
}
}

Any hints, pointers, or working code would be appreciated.


Thanks
Kurt Häusler
MSDN Universal Customer if it helps.

 

[Tejal Joshi \(MSFT\)]

Try writing out the file using FileMode.Open instead of
FileMode.OpenOrCreate.

The first time this command executes (since there is no pre-exsiting file)
it creates the file. Next time however, it opens the already existing file
and overwrites content starting from the beginning of the file. Resulting in
any TRAILING content remaining as is (which is the behavior you see here)
--
This posting is provided "AS IS" with no warranties, and confers no rights.
..


--
This posting is provided "AS IS" with no warranties, and confers no rights.

Hi.

I have a really simple set of classes that writes 2 pathnames to a xml
file. I can write the default ok. Then if I change 1 pathname to a
shorter one, then rewrite the xml file, the remains of the old pathname,
and closing tags are left on the end resulting in an invalid XML file.
XmlSerializer.Deserialize gives a System.InvalidOperationException with
additional information: Error in the XML document.

My default file for example looks like: (sorry about the wrapping if its
wrapped)

ÿþ<?xml version="1.0" encoding="utf-16"?><settings
xmlns:xsd="http://www.w3.org/2001/XMLSchema"

Studio Projects\Initio2_take2\bin\Debug</InstallDir><DataDir>G:\Visual
Studio Projects\Initio2_take2\bin\Debug</DataDir></settings>

After shortening the DataDir path, and rewriting the Xml file, it looks
like this:

ÿþ<?xml version="1.0" encoding="utf-16"?><settings
xmlns:xsd="http://www.w3.org/2001/XMLSchema"

 

[Integer Software]

Hi Tejal.

Changing FileMode.OpenOrCreate to FileMode.Open does not fix the
problem. The wierd behaviour of leaving trailing content remains.

I have never seen this anywhere in programming, by opening a file and
rewriting it, I have NEVER seen trailing content remaining except where
its deliberatly programmed. And it doesnt make any sense at all in a
pre-programmed function like the XML writing functions. I mean surely an
EOF is written in any case right?

I believe this can only be a bug in the functions, and I will attempt to
work around it by deleting the file first.

Thanks anyway.

 

[Tejal Joshi \(MSFT\)]

oops I was typing too fast - I meant use FileMode.Create.
Obviously FileMode.Open would only reopen the existing file and give the
same old behavior!

The documentation for the FileMode enumeration is avialable
http://msdn.microsoft.com/library/d...pref/html/frlrfsystemiofilemodeclasstopic.asp

--
This posting is provided "AS IS" with no warranties, and confers no rights.

Hi Tejal.

Changing FileMode.OpenOrCreate to FileMode.Open does not fix the
problem. The wierd behaviour of leaving trailing content remains.

I have never seen this anywhere in programming, by opening a file and
rewriting it, I have NEVER seen trailing content remaining except where
its deliberatly programmed. And it doesnt make any sense at all in a
pre-programmed function like the XML writing functions. I mean surely an
EOF is written in any case right?

I believe this can only be a bug in the functions, and I will attempt to
work around it by deleting the file first.

Thanks anyway.

here)