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Création d'une archive Zip en mémoire à l'aide de System.IO.Compression

J'essaie de créer une archive Zip avec un simple fichier texte de démonstration en utilisant un MemoryStream comme suit:

using (var memoryStream = new MemoryStream())
using (var archive = new ZipArchive(memoryStream , ZipArchiveMode.Create))
{
    var demoFile = archive.CreateEntry("foo.txt");

    using (var entryStream = demoFile.Open())
    using (var streamWriter = new StreamWriter(entryStream))
    {
        streamWriter.Write("Bar!");
    }

    using (var fileStream = new FileStream(@"C:\Temp\test.Zip", FileMode.Create))
    {
        stream.CopyTo(fileStream);
    }
}

Si j'exécute ce code, le fichier archive lui-même est créé mais foo.txt ne l'est pas.

Toutefois, si je remplace le MemoryStream directement par le flux de fichiers, l’archive est correctement créée:

using (var fileStream = new FileStream(@"C:\Temp\test.Zip", FileMode.Create))
using (var archive = new ZipArchive(fileStream, FileMode.Create))
{
    // ...
}

Est-il possible d'utiliser un MemoryStream pour créer l'archive Zip sans le FileStream?

c#.netzipcompressionziparchive
153
Marius Schulz

Merci à https://stackoverflow.com/a/12350106/222748 J'ai eu:

using (var memoryStream = new MemoryStream())
{
   using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
   {
      var demoFile = archive.CreateEntry("foo.txt");

      using (var entryStream = demoFile.Open())
      using (var streamWriter = new StreamWriter(entryStream))
      {
         streamWriter.Write("Bar!");
      }
   }

   using (var fileStream = new FileStream(@"C:\Temp\test.Zip", FileMode.Create))
   {
      memoryStream.Seek(0, SeekOrigin.Begin);
      memoryStream.CopyTo(fileStream);
   }
}

Nous devons donc appeler dispose sur ZipArchive avant de pouvoir l’utiliser, ce qui signifie de transmettre "true" comme troisième paramètre à ZipArchive afin que nous puissions toujours accéder au flux après l’avoir supprimé.

260
Michael

Juste une autre version de la compression sans écrire aucun fichier.

string fileName = "export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".xlsx";
byte[] fileBytes = here is your file in bytes
byte[] compressedBytes;
string fileNameZip = "Export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".Zip";

using (var outStream = new MemoryStream())
{
    using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
    {
        var fileInArchive = archive.CreateEntry(fileName, CompressionLevel.Optimal);
        using (var entryStream = fileInArchive.Open())
        using (var fileToCompressStream = new MemoryStream(fileBytes))
        {
            fileToCompressStream.CopyTo(entryStream);
        }
    }
    compressedBytes = outStream.ToArray();
}
43
luci79rom

Définissez la position du flux sur 0 avant de le copier dans le flux Zip.

using (var memoryStream = new MemoryStream())
{
 using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
 {
  var demoFile = archive.CreateEntry("foo.txt");

  using (var entryStream = demoFile.Open())
  using (var streamWriter = new StreamWriter(entryStream))
  {
     streamWriter.Write("Bar!");
  }
 }

 using (var fileStream = new FileStream(@"C:\Temp\test.Zip", FileMode.Create))
   {
     memoryStream.Position=0;
     memoryStream.WriteTo(fileStream);
   }
 }
13
Mahesh

Vous devez terminer l'écriture du flux de mémoire, puis relire le tampon.

        using (var memoryStream = new MemoryStream())
        {
            using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create))
            {
                var demoFile = archive.CreateEntry("foo.txt");

                using (var entryStream = demoFile.Open())
                using (var streamWriter = new StreamWriter(entryStream))
                {
                    streamWriter.Write("Bar!");
                }
            }

            using (var fileStream = new FileStream(@"C:\Temp\test.Zip", FileMode.Create))
            {
                var bytes = memoryStream.GetBuffer();
                fileStream.Write(bytes,0,bytes.Length );
            }
        }
6
Rattle

Solution de travail pour MVC

    public ActionResult Index()
    {
        string fileName = "test.pdf";
        string fileName1 = "test.vsix";
        string fileNameZip = "Export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".Zip";

        byte[] fileBytes = System.IO.File.ReadAllBytes(@"C:\test\test.pdf");
        byte[] fileBytes1 = System.IO.File.ReadAllBytes(@"C:\test\test.vsix");
        byte[] compressedBytes;
        using (var outStream = new MemoryStream())
        {
            using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
            {
                var fileInArchive = archive.CreateEntry(fileName, CompressionLevel.Optimal);
                using (var entryStream = fileInArchive.Open())
                using (var fileToCompressStream = new MemoryStream(fileBytes))
                {
                    fileToCompressStream.CopyTo(entryStream);
                }

                var fileInArchive1 = archive.CreateEntry(fileName1, CompressionLevel.Optimal);
                using (var entryStream = fileInArchive1.Open())
                using (var fileToCompressStream = new MemoryStream(fileBytes1))
                {
                    fileToCompressStream.CopyTo(entryStream);
                }


            }
            compressedBytes = outStream.ToArray();
        }
        return File(compressedBytes, "application/Zip", fileNameZip);
    }
5
Debajit Mukhopadhyay
using System;
using System.IO;
using System.IO.Compression;

namespace ConsoleApplication
{
    class Program`enter code here`
    {
        static void Main(string[] args)
        {
            using (FileStream zipToOpen = new FileStream(@"c:\users\exampleuser\release.Zip", FileMode.Open))
            {
                using (ZipArchive archive = new ZipArchive(zipToOpen, ZipArchiveMode.Update))
                {
                    ZipArchiveEntry readmeEntry = archive.CreateEntry("Readme.txt");
                    using (StreamWriter writer = new StreamWriter(readmeEntry.Open()))
                    {
                            writer.WriteLine("Information about this package.");
                            writer.WriteLine("========================");
                    }
                }
            }
        }
    }
}
3
FAREH

Voici le moyen de convertir une entité en fichier XML, puis de le compresser:

private  void downloadFile(EntityXML xml) {

string nameDownloadXml = "File_1.xml";
string nameDownloadZip = "File_1.Zip";

var serializer = new XmlSerializer(typeof(EntityXML));

Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.AddHeader("content-disposition", "attachment;filename=" + nameDownloadZip);

using (var memoryStream = new MemoryStream())
{
    using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
    {
        var demoFile = archive.CreateEntry(nameDownloadXml);
        using (var entryStream = demoFile.Open())
        using (StreamWriter writer = new StreamWriter(entryStream, System.Text.Encoding.UTF8))
        {
            serializer.Serialize(writer, xml);
        }
    }

    using (var fileStream = Response.OutputStream)
    {
        memoryStream.Seek(0, SeekOrigin.Begin);
        memoryStream.CopyTo(fileStream);
    }
}

Response.End();

}

1
luisfbn