如何在ASP.Net核心应用编程接口路由中添加变量前缀？

services.AddRouting(options =>
{
    options.ConstraintMap["prefix"] = typeof(PrefixConstraint);
});

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

public class PrefixConstraint : IRouteConstraint
{
    private readonly string _prefixPattern = @"^[a-zA-Z0-9]+$";

    public bool Match(HttpContext httpContext, IRouter route, string routeKey, RouteValueDictionary values, RouteDirection routeDirection)
    {
        if (values.TryGetValue(routeKey, out var value) && value != null)
        {
            var prefix = value.ToString();
            return Regex.IsMatch(prefix, _prefixPattern);
        }
        return false;
    }
}