使用 ZipArchive 生成Zip文件备注

这个是直接读，直接写，没有问题。--- 

1  public static void TestReadZipAndWriteToNewZip()
 2         {
 3             string path = @"D:\dev\Study\abpio\abp_io\src\Volo.AbpWebSite.Web\TemplateFiles\";
 4             string srcFile = path + "test.zip";
 5             string destFile = path + "test_dest.zip";
 6 
 7             using (var readStream = File.OpenRead(srcFile))
 8             {
 9                 using (var archive = new ZipArchive(readStream, ZipArchiveMode.Read))
10                 {
11                    using (var writeFileStream = new FileStream(destFile, FileMode.CreateNew))
12                     {
13                         using (var outZip = new ZipArchive(writeFileStream, ZipArchiveMode.Create))
14                         {
15                             foreach (var entry_item in archive.Entries)
16                             {
17                                 var new_entry = outZip.CreateEntry(entry_item.FullName);
18                                 using (var stream = new_entry.Open())
19                                 {
20                                     entry_item.Open().CopyTo(stream);
21                                 }
22                             }
23 
24                         }
25                     }
26 
27                 }
28             }
29         }
里边可以注意到多层包裹，整个Zip要有Stream .内部的ZipArctiveEntry也要有留的。

从 ZipArctiveEntry 中读取 内容到字节数组

public static byte[] GetBytes(this ZipArchiveEntry zipFile)
        {
            using (var ms = new MemoryStream())
            {
                using (var stream = zipFile.Open())
                {
                      stream.CopyTo(ms);
                      return  ms.ToArray();
                }
            }
        }

转换为可以处理的 内存文件列表 

 public static FileEntryList ToFileEntryList(this ZipArchive zipFile, string rootFolder = null)
        {
            var zipEntries = zipFile.Entries.ToList();

            if (rootFolder != null)
            {
                zipEntries = zipFile.Entries.Where(entry => 
                entry.FullName.StartsWith(rootFolder)).ToList();
            }
            var fileEntries = new List<FileEntry>();
            foreach (var zipEntry in zipEntries)
            {
                var fileName = zipEntry.FullName;
                if (rootFolder != null)
                {
                     fileName = fileName.RemovePreFix(rootFolder);
                }

                if (fileName.IsNullOrEmpty())
                {
                    continue;
                }
            fileEntries.Add(new FileEntry(fileName, zipEntry.GetBytes(), zipEntry.IsDirectory()); 
            }

            return new FileEntryList(fileEntries);
        }

 private static FileEntryList GetEntriesFromZipFile(string filePath, string rootFolder = null)
        {
            using (var templateFileStream = File.OpenRead(filePath))
            {
       
                using (var archive = new ZipArchive(templateFileStream, ZipArchiveMode.Read))
                {
                   
                    return archive.ToFileEntryList(rootFolder);
                }
            }
        }

  private static byte[] CreateZipFileFromEntries(FileEntryList entries)
        {
            using (var stream = new MemoryStream())
            {
                using (var resultZipFile = new ZipArchive(stream,ZipArchiveMode.Create))
                {
                    entries.CopyToZipFile(resultZipFile);
                   
                }
                //重点在这里：  生成的Zip的流数据返回，一定要在 ZipArchive  的生存期外边！！！！ 
                //如果是直接 写入 FileStream 无所谓 。但要作为 Byte[] 返回 一定要等到释放，或者说，完成压缩后。
                //猜测是 在销毁的时候写入Stream的， 没有看到 ZipArchive 的源码，只能猜测。

                     return stream.ToArray(); 
            }
      }

  虽然花费了不少时间，但总算解决了，~~~~