Azure Functions Demo

This walk-through shows how to use Visual Studio to create and run an Azure Functions project.

The sample project includes two different types of Azure Functions and demonstrates:

• how to trigger a function when an item shows up in a Queue (using a Queue Trigger)
• how to trigger a function when a user posts an HTTP request (using an HTTP Trigger)
• how to configure a local storage queue for testing (using Windows Storage Emulator)
• how to locally debug an Azure Function

The major steps in the tutorial are:

1. Setup Functions Project inside Visual Studio
2. Setup Queue (for Queue Trigger)
3. Test/Debug the Queue Trigger (Locally)
4. Test the Http Trigger (Locally)

Setup Functions Project inside Visual Studio

Option 1: Fetch source from GitHub

• Clone source from GitHub: https://github.com/justcla/AzureFunctionsDemo

Option 2: Setup Project from Scratch

Create New Azure Functions Project (AzureFunctionsDemo)

• File -> New -> Project
  • Visual C# -> Cloud -> Azure Functions
    • Name: "AzureFunctionsDemo"

Create New Function - Http Trigger (HttpTriggerFunction.cs)

• Project -> Add New Item…
  • Visual C# Items -> Azure Function
    • Name: "HttpTriggerFunction.cs"

Create New Function - Queue Trigger (QueueTriggerFunction.cs)

• Project -> Add New Item…
  • Visual C# Items -> Azure Function
    • Name: "QueueTriggerFunction.cs"
    • Connection: "AzureWebJobsStorage"
• Update local.settings.json
  • "AzureWebJobsStorage": "UseDevelopmentStorage=true"

Setup Queue (for Queue Trigger)

• Start Azure Storage Emulator

  • From Windows Status bar
    

• Open Cloud Explorer in Visual Studio

  • View->Cloud Explorer

• Add queue to local storage account

  • Expand: (Local) -> Storage Accounts -> (Development) -> Queues
  • Create Queue: "myqueue-items"
    

Test/Debug the Queue Trigger (Locally)

Run Project (in Debug mode)

• Debug -> Start Debugging (F5)
  Functions Terminal Window will start
  

• Set breakpoint in QueueTriggerFunction.cs (line 12)
  

Add a message to the queue: "Test message 1"

• Open queue: myqueue-items (from Cloud Explorer)
  

• Use the "Add Message" icon - 3rd from the right on queue toolbar

• Enter text into message box: "Test message 1"
  
  Message appears in queue explorer window in Visual Studio
  

Step through code in Visual Studio

• [Wait 10 seconds]
  Program will break on line 12
  

• Debug -> Step Over (F10)
  New messages printed in Functions Terminal Window
  
  Note: "Test message 1" appears printed on the console.

• Debug -> Continue (F5)
  Execution completes.

• Debug -> Stop Debugging (Shift+F5)

Test the Http Trigger (Locally)

• Debug -> Start Debugging (F5)
  Functions Terminal Window will start
  

• Note the URL of the Http Function (HttpTriggerFunction) printed in the terminal window.
  Eg. http://localhost:7071/api/HttpTriggerFunction

• Open a web browser and enter the Http Function URL
  
  Program runs and asks for a "name" parameter.

• Append name parameter to URL query string
  Eg. http://localhost:7071/api/HttpTriggerFunction?name=Harry
  
  Program runs and outputs: "Hello Harry"

• Debug -> Stop Debugging (Shift+F5)