asp.net获取二级域名

using System;
using System.Web;

public class SubdomainHelper
{
    public static string GetSubdomain()
    {
        string host = HttpContext.Current.Request.Url.Host;
        string[] parts = host.Split('.');
        
        if (parts.Length > 2)
        {
            // 假设顶级域名是两个部分（例如 .com, .net）
            return parts[0];
        }
        else
        {
            return null; // 没有二级域名
        }
    }
}

public static string GetSubdomain()
{
    string host = HttpContext.Current.Request.Url.Host;
    string[] parts = host.Split('.');
    
    if (parts.Length > 2 && parts[parts.Length - 2] == "com" && parts[parts.Length - 3] == "example")
    {
        return parts[0];
    }
    else
    {
        return null; // 没有二级域名
    }
}

using System.Web.Mvc;

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new HandleErrorAttribute());
        filters.Add(new CorsFilter());
    }
}

public class CorsFilter : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        filterContext.HttpContext.Response.AddHeader("Access-Control-Allow-Origin", "*");
        filterContext.HttpContext.Response.AddHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
        filterContext.HttpContext.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Authorization");
        base.OnActionExecuting(filterContext);
    }
}