API ASP.NET 5 "POST" successfully, although with the error "No route matches the supplied values"

Question

Even though it looks like a duplicate question, none of the StackOverflow answers seem to fit or solve my problem.

Basically, I'm making a REST API using ASP.NET 5, with two entities: "Server" and "Video", the entity "Video" being dependent on the entity "Server".

The GET, POST, PUT, DELETE... methods are all working with the "Server" entity; the problem is when I try to use POST on the "Video" entity.

System.InvalidOperationException: No route matches the supplied values.
   at Microsoft.AspNetCore.Mvc.CreatedAtActionResult.OnFormatting(ActionContext context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ObjectResultExecutor.ExecuteAsyncCore(ActionContext context, ObjectResult result, Type objectType, Object value)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ObjectResultExecutor.ExecuteAsync(ActionContext context, ObjectResult result)
   at Microsoft.AspNetCore.Mvc.ObjectResult.ExecuteResultAsync(ActionContext context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultAsync(IActionResult result)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeNextResultFilterAsync[TFilter,TFilterAsync]()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

The funny part is that, even though it returns the error, the JSON is being posted successfully when I check with GET.

Here's a chunk of VideosController's code:

namespace SeventhApi.Controllers
{
    [Route("api/servers/{serverId}/videos")]
    [ApiController]
    public class VideosController : ControllerBase
    {
        private readonly VideoContext _context;

        public VideosController(VideoContext context)
        {
            _context = context;
        }

        [HttpGet("{id}")]
        public async Task<ActionResult<Video>> GetVideo(Guid id)
        {
            var video = await _context.Videos.FindAsync(id);

            if (video == null)
            {
                return NotFound();
            }

            return video;
        }

        [HttpPost]
        public async Task<ActionResult<Video>> PostVideo(Video video)
        {
            _context.Videos.Add(video);
            await _context.SaveChangesAsync();

            return CreatedAtAction("GetVideo", new { id = video.VideoId }, video);
        }

And a chunk o the Startup:

        public void ConfigureServices(IServiceCollection services)
        {

            services.AddControllers();
            services.AddDbContext<ServerContext>(opt => opt.UseInMemoryDatabase("Server"));
            services.AddDbContext<VideoContext>(opt => opt.UseInMemoryDatabase("Video"));
        }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseHttpsRedirection();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });

From the answers I've found here, I'm inclined to think it's some routing error, but none of the answers have solved my problem.

Answer 1

url 有两个参数，{serverId} {id}。

return CreatedAtAction("GetVideo", new { id = video.VideoId, serverId = 1 }, video);

Answer 2

As Hazrelle replied, it was really a matter of using nameof(GetVideo):

    [HttpPost]
    [ActionName(nameof(GetVideo))]
    public async Task<ActionResult<Video>> PostVideo(Video video)
    {
        _context.Videos.Add(video);
        await _context.SaveChangesAsync();

        return CreatedAtAction(nameof(GetVideo), new { id = video.VideoId }, video);
    }