Slides from a talk given at the Queensland Azure user group on using Azure Storage with mobile apps, either using the traditional WebApi approach or using the Azure libraries direct from the mobile

5. ASP.NET Server
File Storage
Databases

11. public class AzureStorageHelper
{
string settingName;
string containerName;
bool isPublic;
CloudBlobContainer container = null;
public AzureStorageHelper(string settingName,
string containerName, bool isPublic = true)
{
this.settingName = settingName;
this.containerName = containerName;
this.isPublic = isPublic;
}

12. public CloudBlobContainer GetBlobContainer()
{
if (container != null)
return container;
var connStr = GetConnectionString();
var storageAccount = CloudStorageAccount.Parse(connStr);
var blobClient = storageAccount.CreateCloudBlobClient();
var blobContainer =
blobClient.GetContainerReference(this.containerName);

13. if (blobContainer.CreateIfNotExists())
{
blobContainer.SetPermissions(new BlobContainerPermissions()
{
PublicAccess = isPublic ?
BlobContainerPublicAccessType.Blob :
BlobContainerPublicAccessType.Off
});
}
container = blobContainer;
return blobContainer;
}

14. public string UploadBlob(string filename, Stream stream)
{
if (stream.Length == 0)
throw new ApplicationException("There was no content for the file");
var reference = GetBlobContainer()
.GetBlockBlobReference(filename);
reference.UploadFromStream(stream);
return reference.Uri.AbsoluteUri;
}
Note:The non-async mechanisms are used for this demo for simplicity. Use the async version
for real power. Learn async if you haven’t used it before

16. public void DownloadToStream(string name, Stream stream)
{
Uri ur = new Uri(name);
string fname = Path.GetFileName(ur.LocalPath);
var foundFile = GetBlobContainer().GetBlockBlobReference(fname);
foundFile.DownloadToStream(stream);
}

17. public string UriForFile(string filePath)
{
return container.ServiceClient.BaseUri.AbsoluteUri +
containerName + "/"+ filePath;
}

18. public List<string> ListAllBlobs()
{
return GetBlobContainer()
.ListBlobs()
.Select(item => item.Uri.ToString())
.ToList();
}

19. public void DeleteBlob(string name)
{
Uri ur = new Uri(name);
string fname = Path.GetFileName(ur.LocalPath);
var foundFile = GetBlobContainer().GetBlockBlobReference(fname);
if (foundFile != null)
foundFile.Delete();
}

20. [HttpPost]
[Route("api/ImageService/UploadNewImage")]
public async Task<IHttpActionResult> DirectImageUpload()
{
if (!Request.Content.IsMimeMultipartContent())
throw new
HttpResponseException(Request.CreateResponse(HttpStatusCode.NotAcceptable,
"This request is not properly formatted"));
var provider = new MultipartMemoryStreamProvider();
await Request.Content.ReadAsMultipartAsync(provider);
var file = provider.Contents.First();
var filename = file.Headers.ContentDisposition.FileName.Trim('"');
var stream = await file.ReadAsStreamAsync();
GetAzureStorageConnection().UploadBlob(filename, stream);
return Ok();
}

25. • https://github.com/pierceboggan/Moments
Follow @pierceboggan onTwitter
for updates on the app news

31. • http://azure.microsoft.com/en-us/documentation/services/storage/
• http://azure.microsoft.com/en-us/documentation/videos/azure-storage-5-minute-overview/
• http://manage.windowsazure.com
• http://developer.xamarin.com/guides/cross-platform/azure/
• https://github.com/pierceboggan/Moments