Set 301 HTTPS site

Put code in global.asax file



 void Application_BeginRequest(Object sender, EventArgs e)
    {

        if (Convert.ToString(System.Web.HttpContext.Current.Request.Url).Contains("http://"))
        {
            string strMainurl = Convert.ToString(System.Web.HttpContext.Current.Request.Url);
            HttpContext.Current.Response.StatusCode = 301;
            HttpContext.Current.Response.Status = "301 Moved Permanently";
            HttpContext.Current.Response.AddHeader("Location", strMainurl.Replace("http://", "https://"));

        }
    }