Api Routing in .net core 3.0 - asp.net-core-webapi

Question

I am new to .net core and I want to set a MapRoute to my api.
I config endpoint in startup.cs like
app.UseEndPoints(endpoints=>{
endpoints.MapController("defaultApi","v1/{controller="cont"}/{action}/{id?}");
endpoints.MapController("defaultNonActionApi","v1/{controller="cont"}/{id?}")l
endpoints.MapHealthChecks("/healthz");
});
and in controller.cs
[ApiController]
[Route("[controller]")]
public class contController:ControllerBase{
[HttpGet]
public ActionResult Get(){}
}
The config in useEndpoints is useless, if I goto https://localhost:port/v1/cont it return a 404 and if i goto https://localhost:port/cont it can return an expected result.
It seems like the RouteAttribute override the config in useEndpoints but I can't remove RouteAttribute for an ApiController.
I know change Route("[controller]") to Route("v1/[controller]") can solve this problem, but what I want is something more global that can be configured in startup.cs.
Thanks.

Answer 1

Here is a simple demo like below:
1.Create a custom MvcOptionsExtensions:
public static class MvcOptionsExtensions
{
public static void UseGeneralRoutePrefix(this MvcOptions opts, IRouteTemplateProvider routeAttribute)
{
opts.Conventions.Add(new RoutePrefixConvention(routeAttribute));
}
public static void UseGeneralRoutePrefix(this MvcOptions opts, string prefix)
{
opts.UseGeneralRoutePrefix(new RouteAttribute(prefix));
}
}
public class RoutePrefixConvention : IApplicationModelConvention
{
private readonly AttributeRouteModel _routePrefix;
public RoutePrefixConvention(IRouteTemplateProvider route)
{
_routePrefix = new AttributeRouteModel(route);
}
public void Apply(ApplicationModel application)
{
foreach (var selector in application.Controllers.SelectMany(c => c.Selectors))
{
if (selector.AttributeRouteModel != null)
{
selector.AttributeRouteModel = AttributeRouteModel.CombineAttributeRouteModel(_routePrefix, selector.AttributeRouteModel);
}
else
{
selector.AttributeRouteModel = _routePrefix;
}
}
}
}
2.Register in Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
services.AddControllersWithViews(o => { o.UseGeneralRoutePrefix("v1"); });
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
3.Controller:
[ApiController]
[Route("[controller]")]
public class contController:ControllerBase{
[HttpGet]
public ActionResult Get(){}
}