.NET Core API : No route matches the supplied values

Question

I'm making a Web API and I want to retrieve the object created by the CreateCommand Method.

To do that, I'm using the CreateAtRoute function to call the GetCommandById function ,with the id of the created Command as parameter, but I'm getting the following error:

" System.InvalidOperationException: No route matches the supplied values."

This is my controller:

[Route("api/commands")]
[ApiController]
public class CommandsController : Controller
{
    private readonly ICommanderRepo _repository;
    private readonly IMapper _mapper;

    public CommandsController(ICommanderRepo repository,IMapper mapper)
    {
        _repository = repository;
        _mapper = mapper;
    }

    [HttpGet]
    public ActionResult <IEnumerable<CommandReadDto>> GetAllCommands()
    {
        var commands = _repository.GetAllCommands();
        return Ok(_mapper.Map<IEnumerable<CommandReadDto>>(commands));
    }

    [HttpGet("{id}")]
    public ActionResult <CommandReadDto> GetCommandById(int id)
    {
        var command = _repository.GetCommandById(id);

        if(command != null)
        {
            return Ok(_mapper.Map<CommandReadDto>(command));
        }
        return NotFound();
    }

    [HttpPost]
    public ActionResult <CommandReadDto> CreateCommand(CommandCreateDto commandCreateDto)
    {
        var commandModel = _mapper.Map<Command>(commandCreateDto);
        _repository.CreateCommand(commandModel);
        _repository.SaveChanges();

        var commandReadDto = _mapper.Map<CommandReadDto>(commandModel);
        var x = nameof(GetCommandById);
        return CreatedAtRoute(nameof(GetCommandById), new { id = commandReadDto.Id }, commandReadDto);
    }

I have already tried this (which didn't resolve the problem):

1. Check if the parameters of both functions match
2. Added to my Startup.cs : services.AddControllers(options => options.SuppressAsyncSuffixInActionNames = false); ( I saw this on a post here in Stack Overflow)

What might be the problem?

Answer 1

When using CreatedAtRoute, you'll need something like shown below. Please note the addition of a route name, and use of that route name in CreatedAtRoute.

[HttpGet("{id}", Name="GetCommand")]
public ActionResult <CommandReadDto> GetCommandById(int id)
{
   ... // your code here
}

[HttpPost]
public ActionResult <CommandReadDto> CreateCommand(CommandCreateDto commandCreateDto)
{
    ... // your code here

    return CreatedAtRoute("GetCommand", new { commandReadDto.Id }, commandReadDto);
}

An alternative, is to use CreatedAtAction like shown below. With this approach, a route name is not required.

return CreatedAtAction("GetCommandById", new { commandReadDto.Id }, commandReadDto);

You should derive your API-controllers from ControllerBase instead of Controller. The latter is targeting MVC-controllers.

And I believe you should remove options.SuppressAsyncSuffixInActionNames until you actually need it.