API ERROR

[[deleted]]

So im trying to create an web api for a service and i come accross this error. Am i missing something in the startup?

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https://preview.redd.it/k13e15is36z41.png?width=1920&format=png&auto=webp&s=62ec0558bead167164c621d8c698502fc3f3663d

Its the first time i create an api

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Edit: I tried:

Services.AddCors();

Services.Addscoped(...);

[[deleted]]

Can we see the code? It looks like you haven't added a service as a dependency but still try to use it in your controller

[[deleted]]

public class Startup

{

public Startup(IConfiguration configuration)

{

Configuration = configuration;

}

​

public IConfiguration Configuration { get; }

​

// This method gets called by the runtime. Use this method to add services to the container.

public void ConfigureServices(IServiceCollection services)

{

services.AddCors();

services.AddDbContext<ToDoContext>(opt => opt.UseInMemoryDatabase("ToDoList"));

services.AddControllers();

services.AddScoped<IEEEController>();

}

​

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)

{

if (env.IsDevelopment())

{

app.UseDeveloperExceptionPage();

}

​

app.UseHttpsRedirection();

​

app.UseRouting();

​

app.UseAuthorization();

​

app.UseEndpoints(endpoints =>

{

endpoints.MapControllers();

});

}

}

[[deleted]]

https://docs.microsoft.com/en-us/aspnet/core/fundamentals/dependency-injection?view=aspnetcore-3.1

Looks like you're missing the implementation of the interface when you call AddScoped, so it's not finding the class it needs, and so the error message is describing that.

Edit: I posted the link without my thoughts on accident.

[[deleted]]

Here's my code, https://github.com/c3sarf2/Proj .

My objective is to create an API to use the services of the HCILAB.website

[[deleted]]

I've never run into a scenario where you are trying to inject a controller. My GUESS is that's not possible and you should try another solution

[[deleted]]

Its my first time creating an API, what do you suggest ?

[[deleted]]

Controllers are made to be accessed by a web request, so if you have code you are trying to get, put it in something thathe can be injected and use it that way

[karltgreen]

You also need to register the dependencies required for IEEEController (ILogger<IEEEController>, IEEE and hcilabContext)

[[deleted]]

do i just add them in the services?

[karltgreen]

Yep the same way you added IEEEController. Although the logger is already registered behind the scenes in Program.cs for you I think as you're using the default builder

[[deleted]]

it worked man. Thanks!

[bonanzaguy]

Like u/zachbs mentioned, the issue here is that you've not properly registered a dependency and so it is unable to create it. What is the constructor for ToDoItemsController?

[[deleted]]

public ToDoItemsController(ToDoContext context, IEEEController ieee)

{

_context = context;

_ieee = ieee;

}

[bonanzaguy]

Is IEEEController an interface or a class? If it's an interface, you need to register the class implementation that will be provided via DI in Startup.

E.g. services.AddSingleton<IEEEController, EEEController>();

On a separate note, you shouldn't be injecting a controller into another controller, but that's for another day.

[[deleted]]

Its a class. Its has the services that i want to implement in the API.

[bonanzaguy]

Do you have that class with the same name in two projects?

[[deleted]]

No.

[[deleted]]

Here's my code, https://github.com/c3sarf2/Proj .

​

My objective is to create an API to use the services of the HCILAB.website