How to upload file into Azure Blob Storage using C#?

Question

I have a console app that is written using C# on the top of Core.NET 2.2 framework.

I want to change my storage from local to Azure blob storage. I downloaded WindowsAzure.Storage to connect to my Azure account.

I have the following interface

public interface IStorage
{
    Task Create(Stream stram, string path);
}

I created the following interface as blob container factory

public interface IBlobContainerFactory
{
    CloudBlobContainer Get();
}

and here is my Azure implementation

public class AzureBlobStorage : IStorage
{
    private IBlobContainerFactory ContainerFactory

    public AzureBlobStorage(IBlobContainerFactory containerFactory)
    {
        ContainerFactory = containerFactory;
    }

    public async Task Create(Stream stream, string path)
    {
        CloudBlockBlob blockBlob = ContainerFactory.Get().GetBlockBlobReference(path);

        await blockBlob.UploadFromStreamAsync(stream);
    }
}

Then, in my program.cs file I tried the following

if (Configuration["Default:StorageType"].Equals("Azure", StringComparison.CurrentCultureIgnoreCase))
{
    services.AddSingleton(opts => new AzureBlobOptions
    {
        ConnectionString = Configuration["Storages:Azure:ConnectionString"],
        DocumentContainer = Configuration["Storages:Azure:DocumentContainer"]
    });

    services.AddSingleton<IBlobContainerFactory, DefaultBlobContainerFactory>();
    services.AddScoped<IStorage, AzureBlobStorage>();
}
else
{
    services.AddScoped<IStorage, LocalStorage>();
}

Container = services.BuildServiceProvider();

// Resolve the storage from the IoC container
IStorage storage = Container.GetService<IStorage>();

// Read a local file
using (FileStream file = File.Open(@"C:\Screenshot_4.png", FileMode.Open))
{
    try
    {
        // write it to the storeage
        storage.Create(file, "test/1.png");
    }
    catch (Exception e)
    {

    }
}

However, when I use AzureBlobStorage nothing happens. The file does not get written to the storage and no exceptions are thrown!

How can I troubleshoot it? How can I correctly write the file to the storage?

Please note, when I change the configuration in Default:StorageType to Local the file is written locally as expected. But can't get it to write to the Azure blog.

Are you actually executing the Create method? It looks like you miss awaiting the result in your program.cs at "storage.Create(file, "test/1.png");" — Random
@Random that actually did it! I was not aware that the code will not execute unless I await for it. I thought without awaiting it run in the background on a different thread! — Junior

Random Random · Accepted Answer · 2019-02-04T02:09:59

I've followed this article: https://docs.microsoft.com/en-us/dotnet/api/overview/azure/storage?view=azure-dotnet

public interface IStorage
{
    Task Create(Stream stream, string path);
}

public class AzureBlobStorage : IStorage
{
    public async Task Create(Stream stream, string path)
    {
        // Initialise client in a different place if you like
        string storageConnectionString = "DefaultEndpointsProtocol=https;"
                    + "AccountName=[ACCOUNT]"
                    + ";AccountKey=[KEY]"
                    + ";EndpointSuffix=core.windows.net";

        CloudStorageAccount account = CloudStorageAccount.Parse(storageConnectionString);
        var blobClient = account.CreateCloudBlobClient();

        // Make sure container is there
        var blobContainer = blobClient.GetContainerReference("test");
        await blobContainer.CreateIfNotExistsAsync();

        CloudBlockBlob blockBlob = blobContainer.GetBlockBlobReference(path);
        await blockBlob.UploadFromStreamAsync(stream);
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Put your DI here
        var storage = new AzureBlobStorage();

        // Read a local file
        using (FileStream file = File.Open(@"C:\cartoon.PNG", FileMode.Open))
        {
            try
            {
                // Pattern to run an async code from a sync method
                storage.Create(file, "1.png").ContinueWith(t =>
                {
                    if (t.IsCompletedSuccessfully)
                    {
                        Console.Out.WriteLine("Blob uploaded");
                    }
                }).Wait();
            }
            catch (Exception e)
            {
                // Omitted
            }
        }
    }
}

How to upload file into Azure Blob Storage using C#?

2 Answers