One or more constructors in Home Controller - error

Question

User-945256609 posted

Dear all,

I am getting the following error in asp.net core project. Can somebody let me know how to overcome this error.

InvalidOperationException: Multiple constructors accepting all given argument types have been found in type 'EmployeeManagement.Controllers.HomeController'. There should only be one applicable constructor.

• Microsoft.Extensions.DependencyInjection.ActivatorUtilities.TryFindMatchingConstructor(Type instanceType, Type[] argumentTypes, ref ConstructorInfo matchingConstructor, ref Nullable<int>[] parameterMap)

• Microsoft.Extensions.DependencyInjection.ActivatorUtilities.FindApplicableConstructor(Type instanceType, Type[] argumentTypes, out ConstructorInfo matchingConstructor, out Nullable<int>[] parameterMap)

• Microsoft.Extensions.DependencyInjection.ActivatorUtilities.CreateFactory(Type instanceType, Type[] argumentTypes)

• Microsoft.AspNetCore.Mvc.Controllers.ControllerActivatorProvider.CreateActivator(ControllerActionDescriptor descriptor)

• Microsoft.AspNetCore.Mvc.Controllers.ControllerFactoryProvider.CreateControllerFactory(ControllerActionDescriptor descriptor)

• Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvokerCache.GetCachedResult(ControllerContext controllerContext)

• Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvokerProvider.OnProvidersExecuting(ActionInvokerProviderContext context)

• Microsoft.AspNetCore.Mvc.Infrastructure.ActionInvokerFactory.CreateInvoker(ActionContext actionContext)

• Microsoft.AspNetCore.Mvc.Routing.ActionEndpointFactory+<>c__DisplayClass7_0.<CreateRequestDelegate>b__0(HttpContext context)

• Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext)

• Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)

• Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

code in home controller

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using EmployeeManagement.Models;

namespace EmployeeManagement.Controllers
{
public class HomeController : Controller
{
private readonly ILogger<HomeController> _logger;

public HomeController(ILogger<HomeController> logger)
{
_logger = logger;
}

private readonly IEmployeeRepository _employeeRepository;

public HomeController(IEmployeeRepository employeeRepository)
{
_employeeRepository = employeeRepository;
}

/*public IActionResult Index()
{
return View();
}*/
public string Index()
{
return _employeeRepository.GetEmployee(1).Name;
}

public IActionResult Privacy()
{
return View();
}

[ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
public IActionResult Error()
{
return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
}
}
}

Answer 1

User-945256609 posted

I had commented logger constructor. then the code started working

Answer 2

User1686398519 posted

Hi,  sathyaav

As prompted by the error message you gave: There should only be one applicable constructor.

You should put "IEmployeeRepository" and "ILogger" in a constructor.You could modify your code like this:

public HomeController(ILogger<HomeController> logger, IEmployeeRepository employeeRepository)

        {

            _logger = logger;

            _employeeRepository = employeeRepository;

        }

Best Regards,

YihuiSun

Answer 3

User-945256609 posted

many thanks. I will modify the code as you had advised.

Cheers

Sathya