Mastering Endpoint Routing in ASP.NET Core: Configuration & Examples Prime Vyapar

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Mastering Endpoint Routing in ASP.NET Core: Configuration & Examples

Routing is the process of mapping incoming HTTP requests to application logic in an ASP.NET Core application.

1. What is Routing?

Routing helps direct HTTP requests to controllers, actions, or endpoints.

2. Configuring Routing in ASP.NET Core


var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.UseRouting();

app.UseEndpoints(endpoints => {
    endpoints.MapControllerRoute(
        name: "default",
        pattern: "{controller=Home}/{action=Index}/{id?}");
});

app.Run();

3. Conventional Routing


app.UseEndpoints(endpoints => {
    endpoints.MapControllerRoute(
        name: "custom",
        pattern: "blog/{articleId}",
        defaults: new { controller = "Blog", action = "Details" }
    );
});

4. Attribute Routing


[Route("products")]
public class ProductsController : Controller {
    [HttpGet("{id}")]
    public IActionResult GetProduct(int id) {
        return Content($"Product ID: {id}");
    }
}

5. Endpoint Routing


var app = WebApplication.CreateBuilder(args).Build();

app.UseRouting();

app.UseEndpoints(endpoints => {
    endpoints.MapGet("/hello", async context => {
        await context.Response.WriteAsync("Hello, World!");
    });
});

app.Run();

6. Route Constraints


[HttpGet("details/{id:int}")]
public IActionResult GetOrder(int id) {
    return Content($"Order ID: {id}");
}

7. Custom Route Constraints


public class EvenNumberConstraint : IRouteConstraint {
    public bool Match(HttpContext? httpContext, IRouter? route, string routeKey,
                      RouteValueDictionary values, RouteDirection routeDirection) {
        if (values.TryGetValue(routeKey, out var value) && int.TryParse(value?.ToString(), out int id)) {
            return id % 2 == 0;
        }
        return false;
    }
}

8. Route Parameters and Defaults


app.UseEndpoints(endpoints => {
    endpoints.MapControllerRoute(
        name: "optional",
        pattern: "blog/{id?}",
        defaults: new { controller = "Blog", action = "Details" }
    );
});

9. Route Prefix in Attribute Routing


[Route("api/products")]
public class ProductsController : Controller {
    [HttpGet]
    public IActionResult GetAll() => Content("All Products");
}

10. Generating URLs in ASP.NET Core


public IActionResult Index() {
    string url = Url.Action("Details", "Blog", new { id = 5 });
    return Content($"Generated URL: {url}");
}

Conclusion

Routing directs requests to appropriate actions.
Conventional routing follows predefined patterns.
Attribute routing is defined directly on controllers.
Endpoint routing improves flexibility.