Compress byte[] (Images) using icsharpziplib

Question

Have only one image that is the byte[] bytes and I am trying to compress to Zip for the user to download as far I can see the byte array is saved in the MemoryStream.

The probleam is when I trie to read the buffer of MemoryStream to ImagesAux this way zippedMemoryStream.Read(ImagesAux, 0, 1000000); doesn't work but ImagesAux = zippedMemoryStream.ToArray(); this way allready works ... then stream.Write(ImagesAux, 0, ImagesAux.Length); as to pass the ZipFile to SaveFileDialog doesn't work either get the size of ImagesAux but not the content from what I saw, the ZipFile is created but gives a error of Format not supported in ALZip, can someone point what I'm doing wrong??

    MemoryStream zippedMemoryStream = new MemoryStream();
    ZipOutputStream zipOutputStream;

    zipOutputStream = new ZipOutputStream(zippedMemoryStream, 1000000);
    zipOutputStream.SetLevel(0);
    zipOutputStream.UseZip64 = UseZip64.On;

    byte[] bytes = new byte[stream.Length];
    stream.Read(bytes, 0, (int)stream.Length);

    ZipEntry entry = new ZipEntry(ZipEntry.CleanName(ImageNameServer));//ImageNameServer
    entry.DateTime = DateTime.Now;
    entry.Comment = "Teste";
    entry.ZipFileIndex = 1;
    entry.Size = bytes.Length;

    zipOutputStream.PutNextEntry(entry);
    zipOutputStream.Write(bytes, 0, bytes.Length);
    var something = zipOutputStream.GetType();
    var lvl = zipOutputStream.GetLevel();
    //zippedMemoryStream.Write(bytes, 0, bytes.Length);
    zippedMemoryStream.Read(buffer, 0, bytes.Length);
    MemoryStream auxxpto = new MemoryStream();
    zippedMemoryStream.WriteTo(auxxpto);
    buffer = auxxpto.ToArray();

    private void DataSetDownload(object sender, RoutedEventArgs e)
    {
        var dialog = new SaveFileDialog();
        dialog.Filter = "Zip Files (*.zip)|*.zip";
        dialog.DefaultExt = "zip";
        dialog.DefaultFileName = "DataSet.zip";

        bool? fileSelected = dialog.ShowDialog();
        byte[] ImagesAux = new byte[1000000];

        if (fileSelected == true)
        {
            var value = zippedMemoryStream.CanWrite;
            var read = zippedMemoryStream.CanRead;
            zippedMemoryStream.Read(ImagesAux, 0, 1000000);
            ImagesAux = zippedMemoryStream.ToArray();
            //ZippedFile.Read(ImagesAux, 0, ImagesAux.Length);
            //ImagesAux = zippedMemoryStream.ToArray();
            zipOutputStream.Finish();
            zipOutputStream.Close();

            using (Stream stream = dialog.OpenFile())
            {
                stream.Write(ImagesAux, 0, ImagesAux.Length);
                //stream = zippedMemoryStream.ToArray();
                //stream.Flush();
                //stream.Close();
            }
        }
    }

It doesn't appear that you're changing the zippedMemoryStream position back to 0 before reading. — Kelly Ethridge, May 06 '14 at 21:08
Yes you are right, didn't know that it was in last position at that point fixed but know when it creates the zip.file appears with the right size but still gives error of Format not supported,but thanks for the answer at least closer to get it right. — H.C, May 07 '14 at 13:54
Solved now had the zipOutputStream.Finish(); in the wrong place, edit now to show where it is. — H.C, May 07 '14 at 15:01

score 0 · Answer 1 · answered Jul 01 '15 at 05:15

This code was moved from the question. Answers should be in answers.

Working code.

    MemoryStream zippedMemoryStream = new MemoryStream();
    ZipOutputStream zipOutputStream;

    zipOutputStream = new ZipOutputStream(zippedMemoryStream, 1000000);
    zipOutputStream.SetLevel(0);
    zipOutputStream.UseZip64 = UseZip64.On;

    byte[] bytes = new byte[stream.Length];
    stream.Read(bytes, 0, (int)stream.Length);

    ZipEntry entry = new ZipEntry(ZipEntry.CleanName(ImageNameServer));//ImageNameServer

    zipOutputStream.PutNextEntry(entry);
    zipOutputStream.Write(bytes, 0, bytes.Length);
    zipOutputStream.Finish();
    zipOutputStream.CloseEntry();

    private void DataSetDownload(object sender, RoutedEventArgs e)
    {
        var dialog = new SaveFileDialog();
        dialog.Filter = "Zip Files (*.zip)|*.zip";
        dialog.DefaultExt = "zip";
        dialog.DefaultFileName = "DataSet.zip";

        bool? fileSelected = dialog.ShowDialog();
        byte[] ImagesAux = new byte[1000000];

        if (fileSelected == true)
        {
            var value = zippedMemoryStream.CanWrite;
            var read = zippedMemoryStream.CanRead;
            zippedMemoryStream.Position = 0;
            zippedMemoryStream.Read(ImagesAux, 0, 1000000);

            //ZippedFile.Read(ImagesAux, 0, ImagesAux.Length);
            //ImagesAux = zippedMemoryStream.ToArray();
            zipOutputStream.Finish();
            zipOutputStream.Close();

            using (Stream stream = dialog.OpenFile())
            {
                stream.Write(ImagesAux, 0, ImagesAux.Length);
                //stream = zippedMemoryStream.ToArray();
                //stream.Flush();
                //stream.Close();
            }
        }
    }

Compress byte[] (Images) using icsharpziplib

1 Answers1