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

我正在尝试使用Azures Blob存储来实现以下内容。

1. 将文件上传到Azure Blob存储。
2. 然后发送包含文件的基本64字符串的HTTP响应。

奇怪的部分是我只能让一个工作，因为它会导致另一个取决于我的代码顺序。

        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();
            }
        }

上面的代码将将文件上传到Azure的Blob存储中，但是Base64字符串将为空。

，但是如果我将线blockBlob.UploadFromStream(image.InputStream);放在线上string base64ImageRepresentation = Convert.ToBase64String(fileData);

下方

我会得到base64字符串没问题，但是该文件未正确上传到Azure的Blob存储。

Answer 1

也许您需要在第一次使用后重置流位置？

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