Downloading File as Byte Array From AZURE BLOB Storage in WCF Service

Contract

using System.Collections.Generic;
using System.IO;
using System.ServiceModel;
using WcfService15testapi.Entities;
 
namespace WcfService15testapi
{
    [ServiceContract]
    public interface IService1
    {
        [OperationContract] 
        byte[] DownLoadFileForBLOB(string ContainerName, string fileName);
    }
}

To download file client will have to provide ContainerName and filename to be downloaded.

Service Implementation

Very first you need to add a reference for:

Microsoft.WindowsAzure

Microsoft.WindowsAzure.StorageClient

Second you need to create a connection string to fetch the file from AZURE BLOB.

Connection String "DefaultEndPoint=https;AccountName=
YOURSTORAGEACCOUNTNAME;AccountKey=ACCOUNTKEY"

So if yours:

Storage Account Name = "Test Account "

Storage Account Key = "xxxxxxxxxxxxxxxxxxxxxx/xxxxxxx=="

Then connection string to AZURE Storage account would be:

DefaultEndPoint=https;AccountName= Test Account;AccountKey= xxxxxxxxxxxxxxxxxxxxxx/xxxxxxx==

Container Name

We are going to download files from a public container. Let us say the public container name is TESTCONTAINER. 
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Net;
 using System.Security.Cryptography.X509Certificates;
 using System.Xml.Linq;
 using WcfService15testapi.Entities;
 using Microsoft.WindowsAzure;
 using Microsoft.WindowsAzure.StorageClient; 
 
 namespace WcfService15testapi
 {  
     public class Service1 : IService1
     {
         public byte[]   DownLoadFileForBLOB (string ContainerName, string fileName)
         {          
             CloudStorageAccount cloudStorageAccount = CloudStorageAccount.Parse
             ("DefaultEndpointsProtocol=https;AccountName= Test Account;AccountKey=xxxxxxx==");
             CloudBlobClient cloudBlobClient = cloudStorageAccount.CreateCloudBlobClient();
             CloudBlobContainer cloudBlobContainer = cloudBlobClient.GetContainerReference
     (ContainerName);
             CloudBlob cloudBlob = cloudBlobContainer.GetBlobReference(fileName);
             byte[] byteData = cloudBlob.DownloadByteArray();
             return byteData;
         }
     }
 }

In this way you can return a BLOB file as a byte array in a WCF Service. I hope this article was useful. Thanks for reading.