如何在内存中创建zip文件，从文件字节开始

本文关键字：文件 字节 开始 zip 创建 内存 | 更新日期: 2023-09-27 18:02:05

我尝试用c#在内存中创建一个zip文件，但结果是一个zip文件里面有损坏的文件。所有要压缩的文件都在数据库中。我存储字节。文件为PDF格式。我的代码如下

//[extract bytes and file name for every file]
using (var zipArchiveMemoryStream = new MemoryStream())
{
    using (var zipArchive = new ZipArchive(zipArchiveMemoryStream,
                                           ZipArchiveMode.Create, true))
    {
        foreach (var file in fileData)
        {
            var zipEntry = zipArchive.CreateEntry(file.FileName);
            using (var entryStream = zipEntry.Open())
            {
                using (var tmpMemory = new MemoryStream(file.Bytes))
                {
                    tmpMemory.CopyTo(entryStream);
                };
            }
        }
    }
    zipArchiveMemoryStream.Position = 0;
    result = zipArchiveMemoryStream.GetBuffer();
//[download zip file]

提前感谢您的支持

解:问题是我使用GetBuffer();而不是ToArray (); 

using (var zipArchiveMemoryStream = new MemoryStream())
        {
            using (var zipArchive = new ZipArchive(zipArchiveMemoryStream, ZipArchiveMode.Create, true))
            {
                foreach (var file in fileData)
                {
                    var zipEntry = zipArchive.CreateEntry(file.FileName);
                    using (var entryStream = zipEntry.Open())
                    {
                        using (var tmpMemory = new MemoryStream(file.Bytes))
                        {
                            tmpMemory.CopyTo(entryStream);
                        };
                    }
                }
            }
            zipArchiveMemoryStream.Seek(0, SeekOrigin.Begin);
            result = zipArchiveMemoryStream.ToArray();
        }
        return result;

如何在内存中创建zip文件，从文件字节开始

试着看看这个:使用System.IO.Compression在内存中创建ZIP存档。解决方案如下:

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);
   }
}

它解释了如何在内存中创建zip存档，并包含了另一篇有用文章的链接，该文章解释了如何使用leaveOpen参数来防止流的关闭:

using (MemoryStream zipStream = new MemoryStream())
{
    using (ZipArchive zip = new ZipArchive(zipStream, ZipArchiveMode.Create, true))
    {
        var entry = zip.CreateEntry("test.txt");
        using (StreamWriter sw = new StreamWriter(entry.Open()))
        {
            sw.WriteLine(
            "Etiam eros nunc, hendrerit nec malesuada vitae, pretium at ligula.");
        }
    }
    var file = await Windows.Storage.ApplicationData.Current.LocalFolder.CreateFileAsync(
    "test.zip",
    CreationCollisionOption.ReplaceExisting);
    zipStream.Position = 0;
    using (Stream s = await file.OpenStreamForWriteAsync())
    {
        zipStream.CopyTo(s);
    }
}

我希望这是有帮助的!

编辑

用zipArchiveMemoryStream.ToArray()代替zipArchiveMemoryStream.GetBuffer()

对我来说是这样的:

using (var memoryStream = new MemoryStream())
{
   using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
   {
      var file = archive.CreateEntry("file.json");
      using var entryStream = file.Open();
      using var streamWriter = new StreamWriter(entryStream);
      streamWriter.WriteLine(someJsonLine);
   }
}
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