Hi all,

I posted a couple of weeks ago with what I thought was a problem with
the file system reading accented characters however, after debugging
line by line I have now found the true problem.

I am storing a list of files in an XML file as a sort of database.
Some of these filenames have accented characters (i.e.  á é í ó ú
or ñ).  However, upon writing the filename to the XML file, the
accented character is dropped.  This causes a problem upon re-reading
the filenames because the program can not find the files because their
'saved' filename is now different.  For example, the word "más" is
saved in the XML file as "ms".

Any ideas how I can work around this?  I could strip out the accents
and replace them with their "normal" equivalent i.e. á becomes a.  But
this is a sort of bodge fix as I will lose the link to the original
file.  Also, I can see a scenario where a file may get overwritten
because the modified filename is the same as an existing file perhaps.

So, to put it blunty, I'm stuck!  Help!


Thanks

How are you currently writing data to the XML file?  Which classes are you
using?  It's likely that the problem is caused by a wrong encoding used to
persist the data.

Herfried K. Wagner [MVP] wrote:
I am using the class StreamReader and StreamWriter.  Can I specify the
enconding with these in order to have the accented characters?

The StreamReader and StreamWriter classes have overloaded constructors to
specify the encoding:

public StreamReader ( System.String path , System.Text.Encoding encoding )

public StreamWriter ( System.String path , System.Boolean append ,
System.Text.Encoding encoding )
    Member of System.IO.StreamWriter

You will have to use the System.Text.Encoding.Default encoding.
Show quoteHide quote

Carlos J. Quintero [VB MVP] wrote:
Thanks Carlos for this.  I'll give it a try and post back if it fails.

I assume that the System.Text.Encoding.Default will cater for all
accents and the Ñ ?

The Default encoding uses your Windows code page instead of Unicode. As long
as your Windows code page (Control Panel, Regional Settings) matches the
code page of the computer used to generate the files, it will work.

Carlos J. Quintero [VB MVP] wrote:
Ah, well there is a problem.  I am developing on a computer that is set
to Spanish regional settings but the app very possibly could be
installed on a computer with different regional settings.  Is there a
universal one I could use?

I'd go with 'Encoding.UTF8' or 'Encoding.Unicode' (which is UTF-16).

Hugh,

Have a look at those code tables for Unicode.

OS systems
http://www.microsoft.com/globaldev/reference/oslocversion.mspx

As you can see in the last page, are countries where is spoken Western
European languages, standard using code page 1252.

I hope this helps a little bit?

Cor

The code pages are not per country, but for greater regions or alphabets.
For example, western european languages use code page 1252 (ANSI Latin I) if
I remember correctly. So, if you are exchanging data from, say, France to
Spain, it will work. China or Russia would be a problem, though.

Also, if you know the code page that was used to create the file, you can
create your own encoding instead of using "Default":

new System.Text.Encoding(codepage)

and pass it to your reader.

If you want to avoid the code page mess, then the writer and the reader
should use Unicode, which was invented to avoid this kind of problems.


Ah, well there is a problem.  I am developing on a computer that is set
to Spanish regional settings but the app very possibly could be
installed on a computer with different regional settings.  Is there a
universal one I could use?

Show quote Hide quote I think my safest option is to use unicode as China is one of the
markets that might be targeted in the future.

This raises one other question.  If unicode was invented to avoid all
this, then what is the benefit of NOT using unicode?

Yes, the safest is to use Unicode.

Unicode has the drawback that it increases the size of file since it uses 2
bytes per character, compared to 1 byte per character when using code pages.
It is the price to pay to accommodate all the characters of all
alphabets.... So, NOT using unicode has the benefit of using smaller files.

You may also enjoy this article:

The Absolute Minimum Every Software Developer Absolutely, Positively Must
Know About Unicode and Character Sets (No Excuses!)
http://www.joelonsoftware.com/articles/Unicode.html

Carlos, this is superb.  Thanks.  However, when I read the filenames in
via StreamReader, I add them into a hashtable.  Some of the filenames
are getting added to the hashtable as just
"?????????????????????????????" which when written back via
StreamWriter become what looks like chinese characters.

Any ideas?

p.s. I have specified the same enconding for both writer and reader.

don't worry, i solved it.  it was a typo.

One last thing: the 2 bytes per character for storage that I said is only
when you save as Unicode UTF-16, saving in UTF-8 consumes less space.
Show quoteHide quote

Hi, Hugh,
  I'm not sure what you're code looks like, but you may need to "tokenize" (encode) these characters.  They should be stored or read in as either UTF-8 or Unicode (XML processors are supposed to recognize these).  This should "just work" if you are using the .NET framework's System.Xml code to generate or read an XML document -- you shouldn't have to do anything.  Are you generating your own XML instead, & parsing it on your own?  If so, you will need to do the encoding yourself, and will need to make sure the file you create has the appropriate header detailing the text type -- it sounds like you're translating them to bare ASCII when you're writing them out.  You can use the System.Test.UTF8Encoding class to translate strings between "normal" strings and UTF8, for example. 

Let us know how it goes. (I'll be away for a few days, but will check back when I get back Friday.)

--Matt Gertz--*
VB Compiler Dev Lead

-----Original Message-----
From: Hugh Janus
Posted At: Monday, January 09, 2006 11:41 AM
Posted To: microsoft.public.dotnet.languages.vb
Conversation: Foreign Characters in XML
Subject: Foreign Characters in XML


Hi all,

I posted a couple of weeks ago with what I thought was a problem with
the file system reading accented characters however, after debugging
line by line I have now found the true problem.

I am storing a list of files in an XML file as a sort of database.
Some of these filenames have accented characters (i.e.  =E1 =E9 =ED =F3 =FA
or =F1).  However, upon writing the filename to the XML file, the
accented character is dropped.  This causes a problem upon re-reading
the filenames because the program can not find the files because their
'saved' filename is now different.  For example, the word "m=E1s" is
saved in the XML file as "ms".

Any ideas how I can work around this?  I could strip out the accents
and replace them with their "normal" equivalent i.e. =E1 becomes a.  But
this is a sort of bodge fix as I will lose the link to the original
file.  Also, I can see a scenario where a file may get overwritten
because the modified filename is the same as an existing file perhaps.

So, to put it blunty, I'm stuck!  Help!


Thanks

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