将文件上传到azure blob存储,然后使用文件base64字符串发送http响应不起作用

Question

我试图使用azures blob存储实现以下功能.

1. 将文件上传到azure blob存储.
2. 然后发送包含该文件的base64字符串的http响应.

奇怪的是,我只能使用一个工作,因为它会导致另一个工作,这取决于我的代码的顺序.

        HttpPostedFile image = Request.Files["froalaImage"];
        if (image != null)
        {
            string fileName = RandomString() + System.IO.Path.GetExtension(image.FileName);
            string companyID = Request.Form["companyID"].ToLower();

            // Retrieve storage account from connection string.
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(
                CloudConfigurationManager.GetSetting("StorageConnectionString"));

            // Create the blob client.
            CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

            // Retrieve reference to a previously created container.
            CloudBlobContainer container = blobClient.GetContainerReference(companyID);

            // Create the container if it doesn't already exist.
            container.CreateIfNotExists();

            // Retrieve reference to a blob named "filename".
            CloudBlockBlob blockBlob = container.GetBlockBlobReference(fileName);

            // Create or overwrite the blob with contents from a local file.
            using (image.InputStream)
            {
                blockBlob.UploadFromStream(image.InputStream);
                byte[] fileData = null;
                using (var binaryReader = new BinaryReader(image.InputStream))
                {
                    fileData = binaryReader.ReadBytes(image.ContentLength);
                }
                string base64ImageRepresentation = Convert.ToBase64String(fileData);                   

                // Clear and send the response back to the browser.
                string json = "";
                Hashtable resp = new Hashtable();
                resp.Add("link", "data:image/" + System.IO.Path.GetExtension(image.FileName).Replace(@".", "") + ";base64," + base64ImageRepresentation);
                resp.Add("imgID", "BLOB/" + fileName);
                json = JsonConvert.SerializeObject(resp);
                Response.Clear();
                Response.ContentType = "application/json; charset=utf-8";
                Response.Write(json);
                Response.End();
            }
        }

上面的代码会将文件上传到azure的blob存储,但base64字符串将为空.

但如果我把线放在线blockBlob.UploadFromStream(image.InputStream);下面string base64ImageRepresentation = Convert.ToBase64String(fileData);

我将获得base64字符串没有问题,但文件没有正确上传到azure的blob存储.

Answer 1

也许你需要在第一次使用后重置你的流位置？

image.InputStream.Seek(0, SeekOrigin.Begin);