CODEWITHSUNDEEP
c#asp.net-coreazure-functions
lcj
lcj

Reputation: 1797

Azure Function, Dependency Injection, "there is no argument given that corresponds to the formal parameter", dotnet core

I am trying to call a repository class from an Azure function but I am getting an error

There is no argument given that corresponds to the formal parameter

I copied the repository class structure from a .NET Core Web API project and know this has to do with dependency injection.

The constructor of the repository class looks like this:

public CaseRepository(ILogger<CaseRepository> logger, IConfiguration configuration)
{
    _logger = logger;
    _configuration = configuration;
}

How can I pass this into the static method of an Azure Function as I do with the Web API call like this:

[FunctionName("TestFunction")]
public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
        ILogger log, CaseRepository caseRepository)
{
    // ...
}

Upvotes: 1

Views: 668

Answers (1)

user1672994
user1672994

Reputation: 10849

You can define the dependency declaration in the Startup class as shown in this file and later instead of defining the function as static define it normal class function. In the class constructor inject the required dependency. See this for reference.

Startup class

 [assembly: FunctionsStartup(typeof(YourNamespace.Startup))]

 namespace YourNamespace
 {
   public class Startup : FunctionsStartup
   {
      builder.Services.AddSingleton<ICaseRepository, CaseRepository>();
   }
 }

Usage - here ICaseRepository is injected in the class containing the Azure functions.

public class TestFunction
{
    private readonly ICaseRepository caseRepository;

    public TestFunction(ICaseRepository  caseRepository)
    {
        this.caseRepository= caseRepository;
    }

    [FunctionName("TestFunction")]
    public async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        // ... use caseRepository instance
    }
}

Upvotes: 1

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