Quickstart: Create a C# function in Azure using Visual Studio Code
In this article, you use Visual Studio Code to create a C# class library-based function that responds to HTTP requests. After testing the code locally, you deploy it to the serverless environment of Azure Functions.
Completing this quickstart incurs a small cost of a few USD cents or less in your Azure account.
There's also a CLI-based version of this article.
Configure your environment
Before you get started, make sure you have the following requirements in place:
An Azure account with an active subscription. Create an account for free.
The C# extension for Visual Studio Code.
The Azure Functions extension for Visual Studio Code.
Create your local project
In this section, you use Visual Studio Code to create a local Azure Functions project in C#. Later in this article, you'll publish your function code to Azure.
Choose the Azure icon in the Activity bar, then in the Azure: Functions area, select the Create new project... icon.
Choose a directory location for your project workspace and choose Select.
These steps were designed to be completed outside of a workspace. In this case, do not select a project folder that is part of a workspace.
Provide the following information at the prompts:
Select a language for your function project: Choose
Select a template for your project's first function: Choose
Provide a function name: Type
Provide a namespace: Type
Authorization level: Choose
Anonymous, which enables anyone to call your function endpoint. To learn about authorization level, see Authorization keys.
Select how you would like to open your project: Choose
Add to workspace.
Using this information, Visual Studio Code generates an Azure Functions project with an HTTP trigger. You can view the local project files in the Explorer. To learn more about files that are created, see Generated project files.
Run the function locally
Visual Studio Code integrates with Azure Functions Core tools to let you run this project on your local development computer before you publish to Azure.
To call your function, press F5 to start the function app project. Output from Core Tools is displayed in the Terminal panel.
If you haven't already installed Azure Functions Core Tools, select Install at the prompt. When the Core Tools are installed, your app starts in the Terminal panel. You can see the URL endpoint of your HTTP-triggered function running locally.
With Core Tools running, navigate to the following URL to execute a GET request, which includes
A response is returned, which looks like the following in a browser:
Information about the request is shown in Terminal panel.
Press Ctrl + C to stop Core Tools and disconnect the debugger.
After you've verified that the function runs correctly on your local computer, it's time to use Visual Studio Code to publish the project directly to Azure.
Sign in to Azure
Before you can publish your app, you must sign in to Azure.
If you aren't already signed in, choose the Azure icon in the Activity bar, then in the Azure: Functions area, choose Sign in to Azure.... If you don't already have one, you can Create a free Azure account. Students can create a free Azure account for Students.
If you're already signed in, go to the next section.
When prompted in the browser, choose your Azure account and sign in using your Azure account credentials.
After you've successfully signed in, you can close the new browser window. The subscriptions that belong to your Azure account are displayed in the Side bar.
Publish the project to Azure
In this section, you create a function app and related resources in your Azure subscription and then deploy your code.
Publishing to an existing function app overwrites the content of that app in Azure.
Choose the Azure icon in the Activity bar, then in the Azure: Functions area, choose the Deploy to function app... button.
Provide the following information at the prompts:
Select folder: Choose a folder from your workspace or browse to one that contains your function app. You won't see this if you already have a valid function app opened.
Select subscription: Choose the subscription to use. You won't see this if you only have one subscription.
Select Function App in Azure: Choose
- Create new Function App. (Don't choose the
Advancedoption, which isn't covered in this article.)
Enter a globally unique name for the function app: Type a name that is valid in a URL path. The name you type is validated to make sure that it's unique in Azure Functions.
Select a location for new resources: For better performance, choose a region near you.
When completed, the following Azure resources are created in your subscription, using names based on your function app name:
- A resource group, which is a logical container for related resources.
- A standard Azure Storage account, which maintains state and other information about your projects.
- A consumption plan, which defines the underlying host for your serverless function app.
- A function app, which provides the environment for executing your function code. A function app lets you group functions as a logical unit for easier management, deployment, and sharing of resources within the same hosting plan.
- An Application Insights instance connected to the function app, which tracks usage of your serverless function.
A notification is displayed after your function app is created and the deployment package is applied.
Select View Output in this notification to view the creation and deployment results, including the Azure resources that you created. If you miss the notification, select the bell icon in the lower right corner to see it again.
Run the function in Azure
Back in the Azure: Functions area in the side bar, expand the new function app under your subscription. Expand Functions, right-click (Windows) or Ctrl - click (macOS) on HttpExample, and then choose Copy function URL.
Paste this URL for the HTTP request into your browser's address bar, add the
namequery string as
?name=Functionsto the end of this URL, and then execute the request. The URL that calls your HTTP-triggered function should be in the following format:
The following example shows the response in the browser to the remote GET request returned by the function:
Clean up resources
When you continue to the next step and add an Azure Storage queue binding to your function, you'll need to keep all your resources in place to build on what you've already done.
Otherwise, you can use the following steps to delete the function app and its related resources to avoid incurring any further costs.
In Visual Studio Code, press F1 to open the command palette. In the command palette, search for and select
Azure Functions: Open in portal.
Choose your function app, and press Enter. The function app page opens in the Azure portal.
In the Overview tab, select the named link next to Resource group.
In the Resource group page, review the list of included resources, and verify that they are the ones you want to delete.
Select Delete resource group, and follow the instructions.
Deletion may take a couple of minutes. When it's done, a notification appears for a few seconds. You can also select the bell icon at the top of the page to view the notification.
To learn more about Functions costs, see Estimating Consumption plan costs.
You have used Visual Studio Code to create a function app with a simple HTTP-triggered function. In the next article, you expand that function by adding an output binding. This binding writes the string from the HTTP request to a message in an Azure Queue Storage queue.