Zipping and unzipping

Hi all,

I don't know whether is the best place for posting my message, but it just
drives me crazy and didn't find a better newgroup for this.
I'm using the ICSharpCode.SharpZipLib for zipping a string to a compressed
string and the other way around.

But when I do a compress/uncompress on "Wim Lambrechts" I received "Wae
Daebrec`ts", so it seems a single bit in each byte is turned off.

I'm using the following code for compressing a string into a compressed
string


public static string CompressString (string input)

{

MemoryStream instream = new MemoryStream(Encoding.ASCII.GetBytes(input));

byte[] buffer = new byte[instream.Length];

instream.Read(buffer, 0, buffer.Length);

instream.Close();

MemoryStream outstream = new MemoryStream();

ZipOutputStream s = new ZipOutputStream(outstream);

s.SetLength(9);


ZipEntry entry = new ZipEntry("");

Crc32 crc = new Crc32();

crc.Reset();

crc.Update(buffer);

entry.Size = buffer.Length;

entry.Crc = crc.Value;


s.PutNextEntry(entry);

s.Write(buffer, 0, buffer.Length);

s.Finish();

s.Close();

return (new ASCIIEncoding().GetString(outstream.GetBuffer()));

}



and for uncompressing:



public static string DecompressString2 (string input)

{

MemoryStream instream = new MemoryStream(Encoding.ASCII.GetBytes(input));

MemoryStream outstream = new MemoryStream();

ZipInputStream s = new ZipInputStream(instream);

s.GetNextEntry();

int size = 2048;

byte[] data = new byte[2048];

while (true)

{

size = s.Read(data, 0, data.Length);

if (size > 0)

{

outstream.Write(data, 0, size);

}

else

{

break;

}

}

return (new ASCIIEncoding().GetString(outstream.GetBuffer()));

}


Again, it drives me crazy: any help is welcome !!!

Wim

Since all Windows CE strings are Unicode system-wide, you should use Unicode
encoding rather than ASCII as you have used in the code below.

Peter

--
Peter Foot
Windows Embedded MVP
OpenNETCF.org Senior Advisor
www.inthehand.com | www.opennetcf.org

"wl" <no-spam@no-spam.no-spam> wrote in message
news:%23IpPolWqDHA.2404@TK2MSFTNGP12.phx.gbl...
> Hi all,
>
> I don't know whether is the best place for posting my message, but it just
> drives me crazy and didn't find a better newgroup for this.
> I'm using the ICSharpCode.SharpZipLib for zipping a string to a compressed
> string and the other way around.
>
> But when I do a compress/uncompress on "Wim Lambrechts" I received "Wae
> Daebrec`ts", so it seems a single bit in each byte is turned off.
>
> I'm using the following code for compressing a string into a compressed
> string
>
>
> public static string CompressString (string input)
>
> {
>
> MemoryStream instream = new MemoryStream(Encoding.ASCII.GetBytes(input));
>
> byte[] buffer = new byte[instream.Length];
>
> instream.Read(buffer, 0, buffer.Length);
>
> instream.Close();
>
> MemoryStream outstream = new MemoryStream();
>
> ZipOutputStream s = new ZipOutputStream(outstream);
>
> s.SetLength(9);
>
>
> ZipEntry entry = new ZipEntry("");
>
> Crc32 crc = new Crc32();
>
> crc.Reset();
>
> crc.Update(buffer);
>
> entry.Size = buffer.Length;
>
> entry.Crc = crc.Value;
>
>
> s.PutNextEntry(entry);
>
> s.Write(buffer, 0, buffer.Length);
>
> s.Finish();
>
> s.Close();
>
> return (new ASCIIEncoding().GetString(outstream.GetBuffer()));
>
> }
>
>
>
> and for uncompressing:
>
>
>
> public static string DecompressString2 (string input)
>
> {
>
> MemoryStream instream = new MemoryStream(Encoding.ASCII.GetBytes(input));
>
> MemoryStream outstream = new MemoryStream();
>
> ZipInputStream s = new ZipInputStream(instream);
>
> s.GetNextEntry();
>
> int size = 2048;
>
> byte[] data = new byte[2048];
>
> while (true)
>
> {
>
> size = s.Read(data, 0, data.Length);
>
> if (size > 0)
>
> {
>
> outstream.Write(data, 0, size);
>
> }
>
> else
>
> {
>
> break;
>
> }
>
> }
>
> return (new ASCIIEncoding().GetString(outstream.GetBuffer()));
>
> }
>
>
> Again, it drives me crazy: any help is welcome !!!
>
> Wim
>
>

Peter,

Thanks for the info: I must admit I didn't try it yet in a compact framework
application (is the intention though).
I did change the encoding and now it works !!! Didn't know what it has to do
with the encoding though ?

Thanks again !!!

Wim

"Peter Foot [MVP]" <feedback@nospam-inthehand.com> wrote in message
news:OWvaHqWqDHA.3320@tk2msftngp13.phx.gbl...
> Since all Windows CE strings are Unicode system-wide, you should use
Unicode
> encoding rather than ASCII as you have used in the code below.
>
> Peter
>
> --
> Peter Foot
> Windows Embedded MVP
> OpenNETCF.org Senior Advisor
> www.inthehand.com | www.opennetcf.org
>
> "wl" <no-spam@no-spam.no-spam> wrote in message
> news:%23IpPolWqDHA.2404@TK2MSFTNGP12.phx.gbl...
> > Hi all,
> >
> > I don't know whether is the best place for posting my message, but it
just
> > drives me crazy and didn't find a better newgroup for this.
> > I'm using the ICSharpCode.SharpZipLib for zipping a string to a
compressed
> > string and the other way around.
> >
> > But when I do a compress/uncompress on "Wim Lambrechts" I received "Wae
> > Daebrec`ts", so it seems a single bit in each byte is turned off.
> >
> > I'm using the following code for compressing a string into a compressed
> > string
> >
> >
> > public static string CompressString (string input)
> >
> > {
> >
> > MemoryStream instream = new
MemoryStream(Encoding.ASCII.GetBytes(input));
> >
> > byte[] buffer = new byte[instream.Length];
> >
> > instream.Read(buffer, 0, buffer.Length);
> >
> > instream.Close();
> >
> > MemoryStream outstream = new MemoryStream();
> >
> > ZipOutputStream s = new ZipOutputStream(outstream);
> >
> > s.SetLength(9);
> >
> >
> > ZipEntry entry = new ZipEntry("");
> >
> > Crc32 crc = new Crc32();
> >
> > crc.Reset();
> >
> > crc.Update(buffer);
> >
> > entry.Size = buffer.Length;
> >
> > entry.Crc = crc.Value;
> >
> >
> > s.PutNextEntry(entry);
> >
> > s.Write(buffer, 0, buffer.Length);
> >
> > s.Finish();
> >
> > s.Close();
> >
> > return (new ASCIIEncoding().GetString(outstream.GetBuffer()));
> >
> > }
> >
> >
> >
> > and for uncompressing:
> >
> >
> >
> > public static string DecompressString2 (string input)
> >
> > {
> >
> > MemoryStream instream = new
MemoryStream(Encoding.ASCII.GetBytes(input));
> >
> > MemoryStream outstream = new MemoryStream();
> >
> > ZipInputStream s = new ZipInputStream(instream);
> >
> > s.GetNextEntry();
> >
> > int size = 2048;
> >
> > byte[] data = new byte[2048];
> >
> > while (true)
> >
> > {
> >
> > size = s.Read(data, 0, data.Length);
> >
> > if (size > 0)
> >
> > {
> >
> > outstream.Write(data, 0, size);
> >
> > }
> >
> > else
> >
> > {
> >
> > break;
> >
> > }
> >
> > }
> >
> > return (new ASCIIEncoding().GetString(outstream.GetBuffer()));
> >
> > }
> >
> >
> > Again, it drives me crazy: any help is welcome !!!
> >
> > Wim
> >
> >
>
>