CODEWITHSUNDEEP
c#asp.net-core.net-coredependency-injection
Sandeep Thomas
Sandeep Thomas

Reputation: 4759

AppSettings values cannot read when using dependency injection

first of all I am a very beginner with dependency injection. I am trying to read appsettings.json configuration values from one of my class

here is my code

private readonly IConfiguration _configuration;
public AdoExtract(IConfiguration configuration = null)
{
    _configuration = configuration;
}
public List<ApiAdoProject> ExtractAllWorkitems()
{
    List<ApiAdoProject> projects = new List<ApiAdoProject>();
    projects = GetAllProjects();
    return projects;
    //foreach (var prj in projects)
    //{
    //    string s = prj.name;
    //}
}

List<ApiAdoProject> GetAllProjects()
{
    Uri uri = new Uri("https://dev.azure.com/****");
    VssBasicCredential credentials =
        new VssBasicCredential("", _configuration["PAT"]);

    using (ProjectHttpClient projectHttpClient =
        new ProjectHttpClient(uri, credentials))
    {
        IEnumerable<TeamProjectReference> projects =
            projectHttpClient.GetProjects().Result;
    }
    return null;
}

When I run this _configuration["PAT"] returning null

Here is my appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*",
  "PAT": "mypat",
  "ClientId": "567567567567546",
  "ClientSecret": "",
  "ConnectionStrings": {
    "EpmoDb": "mycd"
  }
}

Here is my startup

public Startup(IConfiguration configuration)
{
    Configuration = configuration;
}

public IConfiguration Configuration { get; }

Code which use adocontroller

namespace EPMO_Toolset_API.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class AdoController : ControllerBase
    {
        private readonly IConfiguration _configuration;
        public AdoController(IConfiguration configuration = null)
        {
            _configuration = configuration;
        }
        // GET: api/<AdoController>
        [HttpGet]
        public List<ApiAdoProject> Get()
        {
            AdoExtract ado = new AdoExtract();
            return ado.ExtractAllWorkitems();
        }

Did I missed anything or what I did wrong

Upvotes: 0

Views: 348

Answers (1)

Caius Jard
Caius Jard

Reputation: 74710

You wouldn't do this:

AdoExtract ado = new AdoExtract();

Because that runs the AdoExtract constructor with a null IConfiguration, and it is AdoExtract that wants to use the configuration, so it can't be null

You would perhaps instead do something more like injecting the IAdoExtract into the controller:

public AdoController(IAdoExtract x)

And have registered the IAdoExtract to AdoExtract in your ConfigureServices, it means that the configured instance will be used because the DI creates the AdoExtract, it sees that it needs an IConfiguration and it knows how to provide it. If you create the AdoExtract yourself you're bypassing this and provding a null configuration instead

    public void ConfigureServices(IServiceCollection services)
    {
        ...
        // decide a suitable lifetime eg Transient/Scoped etc
        services.AddScoped<IAdoExtract, AdoExtract>();
    }

Upvotes: 2

Related Questions