在 ASP.NET CORE 中动态更改路由属性值

Question

I am looking for a way to grammatically change the value of Route attribute.

I have a scenario where the api route should be either :

1. [Route("api/v1/[Controller]")] or
2. [Route("api/xyz/v1/[Controller]")]

based on whether I am running it in debug mode or not.

[Route("api/v1/[Controller]")]
[ApiController]  
public class MyController : BaseController
{
}

I tried adding a variable in Base Controller but realized that I can't access it in Route attribute.

Answer 1

You cannot change the value of an attribute after compilation, as attributes are compile time constants. That's also why you can't use a variable from you controller class as a parameter (unless it is const )

Instead, you can use preprocessor directives to do this like so

#if DEBUG
[Route("api/v1/[Controller]")]
#else
[Route("api/xyz/v1/[Controller]")]
#endif

(You may want to change it around to if RELEASE and also change to routes)

Answer 2

You can do this in your startup.cs

app.UseMvc(routes =>
{
   routes.MapRoute("default", "api/{controller=Home}/{action=Index}/{id?}");
});

Simply make a if statement for debug.

app.UseMvc(routes =>
{
   routes.MapRoute("default", "api/xyz/{controller=Home}/{action=Index}/{id?}");
});

Or UseControllers or whatever you are using.