Upload and Download Image in Windows Azure Blob Storage in MVC 3

I have been spent quite a bit time to find the solution in one of my projects, finally, I am able to crack it in the following way.

1. Firstly create a separate controller class in the MVC project for managing the the operations with Images. I named it as AlbumController.
2. This controller  class contains the action to handle the HttpPostedFile coming from View.
3. I created a Model class for containing all the necessary methods for handling the operations with the Images.

I am going to describe in details for better understanding

public class AlbumController
    {
        private DiskFileStore fileStore = new DiskFileStore();

        public string AsyncUpload()
        {
            try
            {
                return fileStore.SaveUploadedFile(Request.Files[0]);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
     }

In the above code AsyncUpload is the action which is being used to handle the file submitted. I have created a custom model class named DiskFileStore looks like the following. I am using JQuery AsyncUpload plugin to upload my images in my project.

using Microsoft.WindowsAzure;
using Microsoft.WindowsAzure.StorageClient;
using System.Configuration;

internal class DiskFileStore
    {
         private string _downloadsFolder = HostingEnvironment.MapPath("~/Photos/");
        
         public string SaveUploadedFile(HttpPostedFileBase fileBase)
        {
            try
            {
                CloudStorageAccount csa = CloudStorageAccount.Parse(ConfigurationManager.AppSettings["AzureStorageConnectionString"]);
                CloudBlobClient blobStorage = csa.CreateCloudBlobClient();

                var identifier = Guid.NewGuid();
                string identifierInLower = identifier.ToString().ToLower();

                string fileNameFromRequest = fileBase.FileName.ToLower();
                string fileExtension = fileNameFromRequest.Substring(fileNameFromRequest.IndexOf('.'));

                string originalFileName = identifierInLower + fileExtension;

                CloudBlobContainer cbcMain = blobStorage.GetContainerReference("photos");
                cbcMain.CreateIfNotExist();
                CloudBlob mainblob = cbcMain.GetBlobReference(originalFileName);
                mainblob.UploadFromStream(fileBase.InputStream);

                
                // Abhishek: Download the uploaded blob to local file to show the image at UI                
                CloudBlob savedBlob;
                savedBlob = blobStorage.GetBlobReference("photos/" + originalFileName);
                savedBlob.DownloadToFile(_downloadsFolder + originalFileName);

                return originalFileName;
            }
            catch (System.Runtime.InteropServices.ExternalException e)
            {
                throw e;
            }
            catch (Exception ex)
            {

                throw ex;
            }
            finally
            {

            }

        }
    }

In the above file I have done the following changes.

1. I added Windows Azure references to my projects.
2. I added a AzureConnectionString key to theWeb.Config file with the primary key values of my Azure Storage account.
3. I created one folder named Photos under the root directory. ( As I need to to show back the uploaded image asynchronously in the view, hence I need to download the blob back to some local folder as image to take it as the source).
4. Finally I am returning the image name which I am binding in a hidden field present in the view.(On submit of the form data I am saving the hidden field value as the image URL in the database).