Skip to content

Latest commit

 

History

History
602 lines (385 loc) · 24 KB

storage-quickstart-blobs-dotnet.md

File metadata and controls

602 lines (385 loc) · 24 KB
titledescriptionauthorms.authorms.datems.servicems.topicms.devlangms.customai-usagezone_pivot_groups
Quickstart: Azure Blob Storage library - .NET
In this quickstart, you learn how to use the Azure Blob Storage client library for .NET to create a container and a blob in Blob (object) storage. Next, you learn how to download the blob to your local computer, and how to list all of the blobs in a container.
pauljewellmsft
pauljewell
09/13/2024
azure-blob-storage
quickstart
csharp
devx-track-csharp, mode-api, passwordless-dotnet, devx-track-dotnet, ai-video-demo, devx-track-extended-azdevcli
ai-assisted
azure-blob-storage-quickstart-options

Quickstart: Azure Blob Storage client library for .NET

::: zone pivot="blob-storage-quickstart-scratch"

Note

The Build from scratch option walks you step by step through the process of creating a new project, installing packages, writing the code, and running a basic console app. This approach is recommended if you want to understand all the details involved in creating an app that connects to Azure Blob Storage. If you prefer to automate deployment tasks and start with a completed project, choose Start with a template.

::: zone-end

::: zone pivot="blob-storage-quickstart-template"

Note

The Start with a template option uses the Azure Developer CLI to automate deployment tasks and starts you off with a completed project. This approach is recommended if you want to explore the code as quickly as possible without going through the setup tasks. If you prefer step by step instructions to build the app, choose Build from scratch.

::: zone-end

Get started with the Azure Blob Storage client library for .NET. Azure Blob Storage is Microsoft's object storage solution for the cloud, and is optimized for storing massive amounts of unstructured data.

::: zone pivot="blob-storage-quickstart-scratch"

In this article, you follow steps to install the package and try out example code for basic tasks.

::: zone-end

::: zone pivot="blob-storage-quickstart-template"

In this article, you use the Azure Developer CLI to deploy Azure resources and run a completed console app with just a few commands.

::: zone-end

API reference documentation | Library source code | Package (NuGet) | Samples

::: zone pivot="blob-storage-quickstart-scratch"

This video shows you how to start using the Azure Blob Storage client library for .NET.

[!VIDEO cdae65e7-1892-48fe-934a-70edfbe147be]

The steps in the video are also described in the following sections.

::: zone-end

Prerequisites

::: zone pivot="blob-storage-quickstart-scratch"

::: zone-end

::: zone pivot="blob-storage-quickstart-template"

::: zone-end

Setting up

::: zone pivot="blob-storage-quickstart-scratch"

This section walks you through preparing a project to work with the Azure Blob Storage client library for .NET.

Create the project

Create a .NET console app using either the .NET CLI or Visual Studio 2022.

Visual Studio 2022

  1. At the top of Visual Studio, navigate to File > New > Project...

  2. In the dialog window, enter console app into the project template search box and select the first result. Choose Next at the bottom of the dialog.

    :::image type="content" source="media/storage-quickstart-blobs-dotnet/visual-studio-new-console-app.png" alt-text="A screenshot showing how to create a new project using Visual Studio.":::

  3. For the Project Name, enter BlobQuickstart. Leave the default values for the rest of the fields and select Next.

  4. For the Framework, ensure the latest installed version of .NET is selected. Then choose Create. The new project opens inside the Visual Studio environment.

.NET CLI

  1. In a console window (such as cmd, PowerShell, or Bash), use the dotnet new command to create a new console app with the name BlobQuickstart. This command creates a simple "Hello World" C# project with a single source file: Program.cs.

    dotnet new console -n BlobQuickstart

  2. Switch to the newly created BlobQuickstart directory.

    cd BlobQuickstart

  3. Open the project in your desired code editor. To open the project in:

    • Visual Studio, locate and double-click the BlobQuickStart.csproj file.
    • Visual Studio Code, run the following command:
    code .

Install the package

To interact with Azure Blob Storage, install the Azure Blob Storage client library for .NET.

Visual Studio 2022

  1. In Solution Explorer, right-click the Dependencies node of your project. Select Manage NuGet Packages.

  2. In the resulting window, search for Azure.Storage.Blobs. Select the appropriate result, and select Install.

    :::image type="content" source="media/storage-quickstart-blobs-dotnet/visual-studio-add-package.png" alt-text="A screenshot showing how to add a new package using Visual Studio.":::

.NET CLI

Use the following command to install the Azure.Storage.Blobs package:

dotnet add package Azure.Storage.Blobs

If this command to add the package fails, follow these steps:

  • Make sure that nuget.org is added as a package source. You can list the package sources using the dotnet nuget list source command:

    dotnet nuget list source

  • If you don't see nuget.org in the list, you can add it using the dotnet nuget add source command:

    dotnet nuget add source https://api.nuget.org/v3/index.json -n nuget.org

Now that the package source is updated, run the command to install the package.

Set up the app code

Replace the starting code in the Program.cs file so that it matches the following example, which includes the necessary using statements for this exercise.

usingAzure.Storage.Blobs;usingAzure.Storage.Blobs.Models;usingSystem;usingSystem.IO;// See https://aka.ms/new-console-template for more informationConsole.WriteLine("Hello, World!");

::: zone-end

::: zone pivot="blob-storage-quickstart-template"

With Azure Developer CLI installed, you can create a storage account and run the sample code with just a few commands. You can run the project in your local development environment, or in a DevContainer.

Initialize the Azure Developer CLI template and deploy resources

From an empty directory, follow these steps to initialize the azd template, provision Azure resources, and get started with the code:

  • Clone the quickstart repository assets from GitHub and initialize the template locally:

    azd init --template blob-storage-quickstart-dotnet

    You'll be prompted for the following information:

    • Environment name: This value is used as a prefix for all Azure resources created by Azure Developer CLI. The name must be unique across all Azure subscriptions and must be between 3 and 24 characters long. The name can contain numbers and lowercase letters only.

  • Log in to Azure:

    azd auth login

  • Provision and deploy the resources to Azure:

    azd up

    You'll be prompted for the following information:

    • Subscription: The Azure subscription that your resources are deployed to.
    • Location: The Azure region where your resources are deployed.

    The deployment might take a few minutes to complete. The output from the azd up command includes the name of the newly created storage account, which you'll need later to run the code.

Run the sample code

At this point, the resources are deployed to Azure and the project is ready to run. Follow these steps to update the name of the storage account in the code and run the sample console app:

  • Update the storage account name: Navigate to the src directory and edit Program.cs. Find the <storage-account-name> placeholder and replace it with the actual name of the storage account created by the azd up command. Save the changes.
  • Run the project: If you're using Visual Studio, press F5 to build and run the code and interact with the console app. If you're using the .NET CLI, navigate to your application directory, build the project using dotnet build, and run the application using the dotnet run.
  • Observe the output: This app creates a test file in your local data folder and uploads it to a container in the storage account. The example then lists the blobs in the container and downloads the file with a new name so that you can compare the old and new files.

To learn more about how the sample code works, see Code examples.

When you're finished testing the code, see the Clean up resources section to delete the resources created by the azd up command.

::: zone-end

Object model

Azure Blob Storage is optimized for storing massive amounts of unstructured data. Unstructured data doesn't adhere to a particular data model or definition, such as text or binary data. Blob storage offers three types of resources:

  • The storage account
  • A container in the storage account
  • A blob in the container

The following diagram shows the relationship between these resources.

Diagram of Blob storage architecture.

Use the following .NET classes to interact with these resources:

  • BlobServiceClient: The BlobServiceClient class allows you to manipulate Azure Storage resources and blob containers.
  • BlobContainerClient: The BlobContainerClient class allows you to manipulate Azure Storage containers and their blobs.
  • BlobClient: The BlobClient class allows you to manipulate Azure Storage blobs.

Code examples

The sample code snippets in the following sections demonstrate how to perform the following tasks with the Azure Blob Storage client library for .NET:

::: zone pivot="blob-storage-quickstart-scratch"

Important

Make sure you've installed the correct NuGet packages and added the necessary using statements in order for the code samples to work, as described in the setting up section.

::: zone-end

::: zone pivot="blob-storage-quickstart-template"

Note

The Azure Developer CLI template includes a project with sample code already in place. The following examples provide detail for each part of the sample code. The template implements the recommended passwordless authentication method, as described in the Authenticate to Azure section. The connection string method is shown as an alternative, but isn't used in the template and isn't recommended for production code.

::: zone-end

[!INCLUDE storage-quickstart-credential-free-include]

Create a container

Create a new container in your storage account by calling the CreateBlobContainerAsync method on the blobServiceClient object. In this example, the code appends a GUID value to the container name to ensure that it's unique.

::: zone pivot="blob-storage-quickstart-scratch"

Add the following code to the end of the Program.cs file:

::: zone-end

// TODO: Replace <storage-account-name> with your actual storage account namevarblobServiceClient=newBlobServiceClient(newUri("https://<storage-account-name>.blob.core.windows.net"),newDefaultAzureCredential());//Create a unique name for the containerstringcontainerName="quickstartblobs"+Guid.NewGuid().ToString();// Create the container and return a container client objectBlobContainerClientcontainerClient=awaitblobServiceClient.CreateBlobContainerAsync(containerName);

To learn more about creating a container, and to explore more code samples, see Create a blob container with .NET.

Important

Container names must be lowercase. For more information about naming containers and blobs, see Naming and Referencing Containers, Blobs, and Metadata.

Upload a blob to a container

Upload a blob to a container using UploadAsync. The example code creates a text file in the local data directory to upload to the container.

::: zone pivot="blob-storage-quickstart-scratch"

Add the following code to the end of the Program.cs file:

::: zone-end

// Create a local file in the ./data/ directory for uploading and downloadingstringlocalPath="data";Directory.CreateDirectory(localPath);stringfileName="quickstart"+Guid.NewGuid().ToString()+".txt";stringlocalFilePath=Path.Combine(localPath,fileName);// Write text to the fileawaitFile.WriteAllTextAsync(localFilePath,"Hello, World!");// Get a reference to a blobBlobClientblobClient=containerClient.GetBlobClient(fileName);Console.WriteLine("Uploading to Blob storage as blob:\n\t {0}\n",blobClient.Uri);// Upload data from the local file, overwrite the blob if it already existsawaitblobClient.UploadAsync(localFilePath,true);

To learn more about uploading blobs, and to explore more code samples, see Upload a blob with .NET.

List blobs in a container

List the blobs in the container by calling the GetBlobsAsync method.

::: zone pivot="blob-storage-quickstart-scratch"

Add the following code to the end of the Program.cs file:

::: zone-end

Console.WriteLine("Listing blobs...");// List all blobs in the containerawaitforeach(BlobItemblobItemincontainerClient.GetBlobsAsync()){Console.WriteLine("\t"+blobItem.Name);}

To learn more about listing blobs, and to explore more code samples, see List blobs with .NET.

Download a blob

Download the blob we created earlier by calling the DownloadToAsync method. The example code appends the string "DOWNLOADED" to the file name so that you can see both files in local file system.

::: zone pivot="blob-storage-quickstart-scratch"

Add the following code to the end of the Program.cs file:

::: zone-end

// Download the blob to a local file// Append the string "DOWNLOADED" before the .txt extension // so you can compare the files in the data directorystringdownloadFilePath=localFilePath.Replace(".txt","DOWNLOADED.txt");Console.WriteLine("\nDownloading blob to\n\t{0}\n",downloadFilePath);// Download the blob's contents and save it to a fileawaitblobClient.DownloadToAsync(downloadFilePath);

To learn more about downloading blobs, and to explore more code samples, see Download a blob with .NET.

Delete a container

The following code cleans up the resources the app created by deleting the container using DeleteAsync. The code example also deletes the local files created by the app.

The app pauses for user input by calling Console.ReadLine before it deletes the blob, container, and local files. This is a good chance to verify that the resources were created correctly, before they're deleted.

::: zone pivot="blob-storage-quickstart-scratch"

Add the following code to the end of the Program.cs file:

::: zone-end

// Clean upConsole.Write("Press any key to begin clean up");Console.ReadLine();Console.WriteLine("Deleting blob container...");awaitcontainerClient.DeleteAsync();Console.WriteLine("Deleting the local source and downloaded files...");File.Delete(localFilePath);File.Delete(downloadFilePath);Console.WriteLine("Done");

To learn more about deleting a container, and to explore more code samples, see Delete and restore a blob container with .NET.

::: zone pivot="blob-storage-quickstart-scratch"

The completed code

After completing these steps, the code in your Program.cs file should now resemble the following:

Passwordless (Recommended)

usingAzure.Storage.Blobs;usingAzure.Storage.Blobs.Models;usingAzure.Identity;// TODO: Replace <storage-account-name> with your actual storage account namevarblobServiceClient=newBlobServiceClient(newUri("https://<storage-account-name>.blob.core.windows.net"),newDefaultAzureCredential());//Create a unique name for the containerstringcontainerName="quickstartblobs"+Guid.NewGuid().ToString();// Create the container and return a container client objectBlobContainerClientcontainerClient=awaitblobServiceClient.CreateBlobContainerAsync(containerName);// Create a local file in the ./data/ directory for uploading and downloadingstringlocalPath="data";Directory.CreateDirectory(localPath);stringfileName="quickstart"+Guid.NewGuid().ToString()+".txt";stringlocalFilePath=Path.Combine(localPath,fileName);// Write text to the fileawaitFile.WriteAllTextAsync(localFilePath,"Hello, World!");// Get a reference to a blobBlobClientblobClient=containerClient.GetBlobClient(fileName);Console.WriteLine("Uploading to Blob storage as blob:\n\t {0}\n",blobClient.Uri);// Upload data from the local fileawaitblobClient.UploadAsync(localFilePath,true);Console.WriteLine("Listing blobs...");// List all blobs in the containerawaitforeach(BlobItemblobItemincontainerClient.GetBlobsAsync()){Console.WriteLine("\t"+blobItem.Name);}// Download the blob to a local file// Append the string "DOWNLOADED" before the .txt extension // so you can compare the files in the data directorystringdownloadFilePath=localFilePath.Replace(".txt","DOWNLOADED.txt");Console.WriteLine("\nDownloading blob to\n\t{0}\n",downloadFilePath);// Download the blob's contents and save it to a fileawaitblobClient.DownloadToAsync(downloadFilePath);// Clean upConsole.Write("Press any key to begin clean up");Console.ReadLine();Console.WriteLine("Deleting blob container...");awaitcontainerClient.DeleteAsync();Console.WriteLine("Deleting the local source and downloaded files...");File.Delete(localFilePath);File.Delete(downloadFilePath);Console.WriteLine("Done");

Connection String

usingAzure.Storage.Blobs;usingAzure.Storage.Blobs.Models;// TODO: Replace <storage-account-name> with your actual storage account namevarblobServiceClient=newBlobServiceClient("<storage-account-connection-string>");//Create a unique name for the containerstringcontainerName="quickstartblobs"+Guid.NewGuid().ToString();// Create the container and return a container client objectBlobContainerClientcontainerClient=awaitblobServiceClient.CreateBlobContainerAsync(containerName);// Create a local file in the ./data/ directory for uploading and downloadingstringlocalPath="data";Directory.CreateDirectory(localPath);stringfileName="quickstart"+Guid.NewGuid().ToString()+".txt";stringlocalFilePath=Path.Combine(localPath,fileName);// Write text to the fileawaitFile.WriteAllTextAsync(localFilePath,"Hello, World!");// Get a reference to a blobBlobClientblobClient=containerClient.GetBlobClient(fileName);Console.WriteLine("Uploading to Blob storage as blob:\n\t {0}\n",blobClient.Uri);// Upload data from the local fileawaitblobClient.UploadAsync(localFilePath,true);Console.WriteLine("Listing blobs...");// List all blobs in the containerawaitforeach(BlobItemblobItemincontainerClient.GetBlobsAsync()){Console.WriteLine("\t"+blobItem.Name);}// Download the blob to a local file// Append the string "DOWNLOADED" before the .txt extension // so you can compare the files in the data directorystringdownloadFilePath=localFilePath.Replace(".txt","DOWNLOADED.txt");Console.WriteLine("\nDownloading blob to\n\t{0}\n",downloadFilePath);// Download the blob's contents and save it to a fileawaitblobClient.DownloadToAsync(downloadFilePath);// Clean upConsole.Write("Press any key to begin clean up");Console.ReadLine();Console.WriteLine("Deleting blob container...");awaitcontainerClient.DeleteAsync();Console.WriteLine("Deleting the local source and downloaded files...");File.Delete(localFilePath);File.Delete(downloadFilePath);Console.WriteLine("Done");

Run the code

This app creates a test file in your local data folder and uploads it to Blob storage. The example then lists the blobs in the container and downloads the file with a new name so that you can compare the old and new files.

If you're using Visual Studio, press F5 to build and run the code and interact with the console app. If you're using the .NET CLI, navigate to your application directory, then build and run the application.

dotnet build
dotnet run

The output of the app is similar to the following example (GUID values omitted for readability):

Azure Blob Storage - .NET quickstart sample Uploading to Blob storage as blob: https://mystorageacct.blob.core.windows.net/quickstartblobsGUID/quickstartGUID.txt Listing blobs... quickstartGUID.txt Downloading blob to ./data/quickstartGUIDDOWNLOADED.txt Press any key to begin clean up Deleting blob container... Deleting the local source and downloaded files... Done

Before you begin the clean-up process, check your data folder for the two files. You can open them and observe that they're identical.

::: zone-end

Clean up resources

::: zone pivot="blob-storage-quickstart-scratch"

After you verify the files and finish testing, press the Enter key to delete the test files along with the container you created in the storage account. You can also use Azure CLI to delete resources.

::: zone-end

::: zone pivot="blob-storage-quickstart-template"

When you're done with the quickstart, you can clean up the resources you created by running the following command:

azd down

You'll be prompted to confirm the deletion of the resources. Enter y to confirm.

::: zone-end

Next step

[!div class="nextstepaction"] Azure Storage samples and developer guides for .NET

close