问dotnetzip创建空损坏文件
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Stack Overflow用户

提问于 2018-11-29 08:45:52

回答 1查看 371关注 0票数 0

我正在尝试创建一个HTTP触发函数，它将从Azure存储中取出一个blob，将其压缩，然后将zip重新上传到blob存储中。在这条路上的某个地方这是不对的。它成功地压缩和重新上传，但压缩文件有0KB的内容，不能打开。任何帮助都将不胜感激。找到下面的代码。

 public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)]HttpRequestMessage req, TraceWriter log)
    {
        log.Info("C# HTTP trigger function processed a request.");
        try
        {
          string fileName = req.GetQueryNameValuePairs()
                .FirstOrDefault(q => string.Compare(q.Key, "fileName", true) == 0)
                .Value;

            log.Info($"fileName: {fileName}");

            dynamic request = await req.Content.ReadAsAsync<object>();
            var container = (string)request.body;

            string connectionString = Environment.GetEnvironmentVariable("blobstorageconnectionstring");
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);
            CloudBlobClient client = storageAccount.CreateCloudBlobClient();

            MemoryStream outputStream = new MemoryStream();

            using (ZipFile zip = new ZipFile())
            {
                zip.AddEntry($"{fileName}.xlsx", DownloadFromBlobStorage(fileName, connectionString, container));
                zip.CompressionMethod = CompressionMethod.Deflate;
                zip.Save(outputStream);
            }


            UploadToBlobStorage(fileName + "ZIP", outputStream, connectionString, container);

            return req.CreateResponse(HttpStatusCode.OK, "OK");
        }
        catch (Exception ex)
        {
            log.Error("error", ex: ex);

            return req.CreateResponse(HttpStatusCode.BadRequest);
        }

    }
    private static void UploadToBlobStorage(string name, MemoryStream dataStream, string storageConnectionString, string blobContainerName)
    {

        CloudStorageAccount account = CloudStorageAccount.Parse(storageConnectionString);
        CloudBlobClient client = account.CreateCloudBlobClient();

        CloudBlobContainer container = client.GetContainerReference(blobContainerName);
        container.CreateIfNotExists();

        CloudBlockBlob blob = container.GetBlockBlobReference(name);
        blob.Properties.ContentType = "application/x-zip-compressed";

        dataStream.Position = 0;
        blob.UploadFromStream(dataStream);
    }
    private static MemoryStream DownloadFromBlobStorage(string fileName, string storageConnectionString, string blobContainerName)
    {

        CloudStorageAccount account = CloudStorageAccount.Parse(storageConnectionString);
        CloudBlobClient client = account.CreateCloudBlobClient();

        CloudBlobContainer container = client.GetContainerReference(blobContainerName);
        container.CreateIfNotExists();

        CloudBlockBlob blob = container.GetBlockBlobReference(fileName);

        MemoryStream memStream = new MemoryStream();

        blob.DownloadToStream(memStream);

        return memStream;
    }

.net

dotnetzip

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回答 1

Stack Overflow用户

回答已采纳

发布于 2018-11-29 09:19:29

似乎您也应该将从MemoryStream返回的DownloadFromBlobStorage()对象定位为零(您已经在UploadToBlobStorage()上使用了outputStream/dataStream )，然后将它传递给zip.AddEntry()。

   MemoryStream inputStream = DownloadFromBlobStorage(fileName, connectionString, container);
   inputStream.Position = 0;
   zip.AddEntry($"{fileName}.xlsx", inputStream);