I’m trying to consume my asp.net web api in my asp.net core mvc web app which are on the same solution. I configured the solution for multi-project start and they start both.
next I tried to consume the API in the Web part but I’m getting the following error.
InvalidOperationException: A suitable constructor for type ‘ProjectName.Web.Services.Interfaces.IAdminService’ could not be located. Ensure the type is concrete and all parameters of a public constructor are either registered as services or passed as arguments. Also ensure no extraneous arguments are provided.
Microsoft.Extensions.DependencyInjection.ActivatorUtilities.FindApplicableConstructor(Type instanceType, Type[] argumentTypes, out ConstructorInfo matchingConstructor, out Nullable[] matchingParameterMap)
Here is the complete Stack trace
The Projects are structure like this
SolutionName:
Name.API
Name.Web
each with its own respective structure
This is my Helper Class
public static class HttpClientExtensions
{
public static async Task<T> ReadContentAsync<T>(this HttpResponseMessage response)
{
//if (response.IsSuccessStatusCode == false) return StatusCodes = 300;
//throw new ApplicationException($"Something went wrong calling the API: {response.ReasonPhrase}");
var dataAsString = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
var result = JsonSerializer.Deserialize<T>(
dataAsString, new JsonSerializerOptions
{
PropertyNameCaseInsensitive = true
});
return result;
}
}
The IAdmin Inter Face
Task<IEnumerable<Admins>> GetAllAdmins();
The AdminService(Implementation)
private readonly HttpClient _client;
public const string BasePath = "api/Admins";
public AdminService(HttpClient client)
{
_client = client; // ?? throw new ArgumentNullException(nameof(client));
}
public async Task<IEnumerable<Admins>> GetAllAdmins()
{
var response = await _client.GetAsync(BasePath);
return await response.ReadContentAsync<List<Admins>>();
}
Admins Controller
private readonly IAdminService _adminService;
public AdminController(IAdminService adminService)
{
_adminService = adminService;
}
public async Task<IActionResult> Index()
{
var adminsList = await _adminService.GetAllAdmins();
if(adminsList == null)
{
return new JsonResult("There are now Admins");
}
return View(adminsList);
}
Program.cs
builder.Services.AddControllersWithViews();
builder.Services.AddHttpClient<IAdminService, IAdminService>(c =>
c.BaseAddress = new Uri("https://localhost:<port-Num>/"));
var app = builder.Build();
What Could I be doing wrong???
I’m using .NET 6
adn both Projects are in the same solution
NB My end points are working fine, I test them using Postman.
2
Answers
It is failing because DI cannot instantiate your AdminService with parameterized constructor. This is possibly a duplicate of Combining DI with constructor parameters? .
Essentially, you should avoid parameterized constructor injection where possible. Either control it through configuration or have the configuration loaded through common infrastructure such as host configuration.
According to your codes, I found you put two interface inside the AddHttpClient method which caused the issue.
I suggest you could modify it like this and then it will work well.