Using 'UseMvc' to configure MVC is not supported while using Endpoint Routing
This worked for me (add in Startup.cs
> ConfigureServices method):
services.AddMvc(option => option.EnableEndpointRouting = false)
I found the solution, in the following official documentation "Migrate from ASP.NET Core 2.2 to 3.0":
There are 3 approaches:
- Replace UseMvc or UseSignalR with UseEndpoints.
In my case, the result looked like that
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
//Old Way
services.AddMvc();
// New Ways
//services.AddRazorPages();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseStaticFiles();
app.UseRouting();
app.UseCors();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute("default", "{controller=Home}/{action=Index}");
});
}
}
OR
2. Use AddControllers() and UseEndpoints()
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseStaticFiles();
app.UseRouting();
app.UseCors();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
OR
3. Disable endpoint Routing. As the exception message suggests and as mentioned in the following section of documentation: use mvcwithout endpoint routing
services.AddMvc(options => options.EnableEndpointRouting = false);
//OR
services.AddControllers(options => options.EnableEndpointRouting = false);
but I need to know what is the proper way to solve it
In general, you should use EnableEndpointRouting
instead of UseMvc
, and you could refer Update routing startup code for detail steps to enable EnableEndpointRouting
.
why Endpoint Routing does not need UseMvc() function.
For UseMvc
, it uses the IRouter-based logic
and EnableEndpointRouting
uses endpoint-based logic
. They are following different logic which could be found below:
if (options.Value.EnableEndpointRouting)
{
var mvcEndpointDataSource = app.ApplicationServices
.GetRequiredService<IEnumerable<EndpointDataSource>>()
.OfType<MvcEndpointDataSource>()
.First();
var parameterPolicyFactory = app.ApplicationServices
.GetRequiredService<ParameterPolicyFactory>();
var endpointRouteBuilder = new EndpointRouteBuilder(app);
configureRoutes(endpointRouteBuilder);
foreach (var router in endpointRouteBuilder.Routes)
{
// Only accept Microsoft.AspNetCore.Routing.Route when converting to endpoint
// Sub-types could have additional customization that we can't knowingly convert
if (router is Route route && router.GetType() == typeof(Route))
{
var endpointInfo = new MvcEndpointInfo(
route.Name,
route.RouteTemplate,
route.Defaults,
route.Constraints.ToDictionary(kvp => kvp.Key, kvp => (object)kvp.Value),
route.DataTokens,
parameterPolicyFactory);
mvcEndpointDataSource.ConventionalEndpointInfos.Add(endpointInfo);
}
else
{
throw new InvalidOperationException($"Cannot use '{router.GetType().FullName}' with Endpoint Routing.");
}
}
if (!app.Properties.TryGetValue(EndpointRoutingRegisteredKey, out _))
{
// Matching middleware has not been registered yet
// For back-compat register middleware so an endpoint is matched and then immediately used
app.UseEndpointRouting();
}
return app.UseEndpoint();
}
else
{
var routes = new RouteBuilder(app)
{
DefaultHandler = app.ApplicationServices.GetRequiredService<MvcRouteHandler>(),
};
configureRoutes(routes);
routes.Routes.Insert(0, AttributeRouting.CreateAttributeMegaRoute(app.ApplicationServices));
return app.UseRouter(routes.Build());
}
For EnableEndpointRouting
, it uses EndpointMiddleware to route the request to the endpoints.