C#でのAzure Functionsの利用方法を徹底解説

npm install -g azure-functions-core-tools@3 --unsafe-perm true

using System.IO;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;

public static class HttpTriggerFunction
{
    [FunctionName("HttpTriggerFunction")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        log.LogInformation("C# HTTP trigger function processed a request.");

        string name = req.Query["name"];

        string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
        dynamic data = JsonConvert.DeserializeObject(requestBody);
        name = name ?? data?.name;

        return name != null
            ? (ActionResult)new OkObjectResult($"Hello, {name}")
            : new BadRequestObjectResult("Please pass a name on the query string or in the request body");
    }
}

http://localhost:7071/api/HttpTriggerFunction?name=Azure

[FunctionName("HttpTriggerFunction")]
public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
    ILogger log)
{
    log.LogInformation("HTTP trigger function processed a request.");
    // Function code
}

[FunctionName("TimerTriggerFunction")]
public static void Run(
    [TimerTrigger("0 */5 * * * *")] TimerInfo myTimer, ILogger log)
{
    log.LogInformation($"Timer trigger function executed at: {DateTime.Now}");
    // Function code
}

[FunctionName("QueueTriggerFunction")]
public static void Run(
    [QueueTrigger("my-queue", Connection = "AzureWebJobsStorage")] string myQueueItem, ILogger log)
{
    log.LogInformation($"Queue trigger function processed: {myQueueItem}");
    // Function code
}

[FunctionName("BlobTriggerFunction")]
public static void Run(
    [BlobTrigger("samples-workitems/{name}", Connection = "AzureWebJobsStorage")] Stream myBlob, string name, ILogger log)
{
    log.LogInformation($"Blob trigger function processed blob\n Name: {name} \n Size: {myBlob.Length} Bytes");
    // Function code
}

[FunctionName("EventHubTriggerFunction")]
public static void Run(
    [EventHubTrigger("myeventhub", Connection = "EventHubConnectionAppSetting")] EventData[] events, ILogger log)
{
    foreach (EventData eventData in events)
    {
        string messageBody = Encoding.UTF8.GetString(eventData.Body.Array);
        log.LogInformation($"Event Hub trigger function processed a message: {messageBody}");
        // Function code
    }
}

az login

func azure functionapp publish <FunctionAppName>

public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
    ILogger log)
{
    try
    {
        log.LogInformation("C# HTTP trigger function processed a request.");
        string name = req.Query["name"];
        string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
        dynamic data = JsonConvert.DeserializeObject(requestBody);
        name = name ?? data?.name;

        if (string.IsNullOrEmpty(name))
        {
            throw new ArgumentNullException("name", "Name parameter is missing.");
        }

        return new OkObjectResult($"Hello, {name}");
    }
    catch (Exception ex)
    {
        log.LogError($"Something went wrong: {ex.Message}");
        return new StatusCodeResult(StatusCodes.Status500InternalServerError);
    }
}

http://localhost:7071/api/HttpTriggerFunction?name=Azure

[FunctionName("RegisterUser")]
public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "post", Route = null)] HttpRequest req,
    ILogger log)
{
    log.LogInformation("RegisterUser function processed a request.");

    string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
    User user = JsonConvert.DeserializeObject<User>(requestBody);

    if (string.IsNullOrEmpty(user.Name) || string.IsNullOrEmpty(user.Email))
    {
        return new BadRequestObjectResult("Please provide a valid name and email.");
    }

    // Save user to database (example code, replace with actual implementation)
    await SaveUserToDatabase(user);

    return new OkObjectResult("User registered successfully.");
}

[FunctionName("ResizeImage")]
public static async Task Run(
    [BlobTrigger("images/{name}", Connection = "AzureWebJobsStorage")] Stream image, string name, ILogger log)
{
    log.LogInformation($"Processing blob\n Name:{name} \n Size: {image.Length} Bytes");

    using (var output = new MemoryStream())
    {
        // Resize image logic (example code, replace with actual implementation)
        await ResizeImage(image, output);

        // Save resized image to a different blob container
        await SaveResizedImage(output, name);
    }
}

[FunctionName("BackupDatabase")]
public static void Run(
    [TimerTrigger("0 0 2 * * *")] TimerInfo myTimer, ILogger log)
{
    log.LogInformation($"BackupDatabase function executed at: {DateTime.Now}");

    // Backup database logic (example code, replace with actual implementation)
    BackupDatabase();
}

public static class Utilities
{
    public static async Task<string> ReadRequestBodyAsync(HttpRequest req)
    {
        using (var reader = new StreamReader(req.Body))
        {
            return await reader.ReadToEndAsync();
        }
    }
}

public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
    ILogger log)
{
    log.LogInformation("Function processed a request.");

    try
    {
        // Function logic
    }
    catch (Exception ex)
    {
        log.LogError($"Error occurred: {ex.Message}");
        return new StatusCodeResult(StatusCodes.Status500InternalServerError);
    }
}

public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
    ILogger log,
    ExecutionContext context)
{
    var config = new ConfigurationBuilder()
        .SetBasePath(context.FunctionAppDirectory)
        .AddJsonFile("local.settings.json", optional: true, reloadOnChange: true)
        .AddEnvironmentVariables()
        .Build();

    string mySetting = config["MySetting"];
    log.LogInformation($"MySetting: {mySetting}");

    // Function logic
}