No parameterless constructor defined for this object error in asp .net MVC-CodePudding

hello guys I have problem with this error. my project is simple I have an Interface called "IApiService" and I have a class called Api that is relative with my IApiService Interface. So in "Api" I have a method that post an api and I think this error doesn't relative with my error. I think error is in my Controller. So I will put my controller code so you guys could help me with! Here it is:

public class HomeController : Controller
    {
        IApiService _apiService;
        public HomeController(IApiService apiService)
        {
            _apiService = apiService;
        }
        // GET: Home
        public async Task<ActionResult> Index(CheckOutViewModel model)
        {
            var result = await _apiService.CheckOut(model);
            return View();
        }
    }

CodePudding user response：

For asp.net framework:

The difference is that you should have your controller like this, no need to inject dependency:

public class HomeController : Controller
{
    IApiService _apiService;

    public HomeController() : this(new ApiService())
    {
    }

    public HomeController(IApiService apiService)
    {
        _apiService = apiService;
    }

    public string getString(string name) {
        string a = _apiService.CheckOut(name);
        return a;
    }
}

==============================================

Please allow me to show a sample here, asp.net core.

My Controller:

public class HomeController : Controller
{
    private readonly IApiService _apiService;

    public HomeController( IApiService iapiService)
    {
        _apiService = iapiService;
    }
    
    public string getString(string name) {
        string a = _apiService.CheckOut(name);
        return a;
    }
}

My interface:

namespace WebMvcApp.Services
{
    public interface IApiService
    {
        public string CheckOut(string str);
    }
}

My implement of the interface:

namespace WebMvcApp.Services
{
    public class ApiService: IApiService
    {
        public string CheckOut(string str)
        {
            return "hello : "   str;        
        }
    }
}

I inject the dependency in startup.cs -> ConfigureServices method:

public void ConfigureServices(IServiceCollection services)
{
    services.AddControllersWithViews();
    services.AddScoped<IApiService, ApiService>();
}

or in .net 6 in Program.cs file:

builder.Services.AddControllersWithViews();
builder.Services.AddScoped<IApiService, ApiService>();