SharpDevelop Community

Hi,

 I am hitting my head at the wall and pulling my hair trying to figure out why since the xap format is a .zip file, I can't extract any files from it using the SharpZipLib (which by the way is great!). I get a message saying the compression method is not supported (256), I have tried to look for such a compression method but in the WinZip website mentions type 96 and 97 if I remember well, but nothing like 256.

 This is very confusing since even the windows explorer can view the contents of the xap file when it is renamed as a zip file. (I also did that before openning the file with my program). 

The exact exception is:

                                                 "Library cannot extract this entry. Version required is (256)"

Here is the C# code:

        private void UnpackDll(String pXapFileName)
        {
            // pXapFileName includes the whole Path, ex. "C:\XapFiles\xyz.xap"

            String sDllFullPath = pXapFileName.Replace(".zip", ".dll");
            String sDllName = Path.GetFileName(pXapFileName).Replace(".zip", ".dll");
            String sOutputDirectory = Path.GetDirectoryName(pXapFileName);
           

            ZipInputStream OZIS = new ZipInputStream(File.OpenRead(pXapFileName));

            ZipEntry OZE = OZIS.GetNextEntry();

            while (OZE != null)
            {
                String sFileName = Path.GetFileName(OZE.Name);

                if (sFileName == sDllName)
                {
                    FileStream OFS = File.Create(sDllFullPath);
                    int iByteCounter = 2048;
                    Byte[ aBlock = new Byte[2048];

                    while (true)
                    {
                        iByteCounter = OZIS.Read(aBlock, 0, aBlock.Length);
                        if (iByteCounter > 0)
                        {
                            OFS.Write(aBlock, 0, iByteCounter);
                        }
                        else
                        {
                            break;
                        }
                    }
                }

                OZE = OZIS.GetNextEntry();
            }
        }

Is it something I am doing wrong?  does SharpZipLib doesn't extract this kind of compression?  Is there any workaround or some small modification I can do to the source code in order to make it work?

Any help will be greatly appreciated     

 Thanks in advance.

Hi,

The version required thing is a strong hint that "something is rotten in the state of Denmark" as some geezer once wrote.

First off tweak your code to just dump the names/dates etc of the entries and  if that works it implies the version required to extract is non-standard.

Your code is ok although its assuming thatthe entry it gets can be decompressed. Folder/directoriesand other oddballs like labels cannot be decompressed.

hth, -jr-