public IActionResult Create(Constant constant)
 {
     if (HttpContext.Session.GetString("Name") == null)
     {
         return(RedirectToAction("Login", "Admin"));
     }
     if (constant.Id == 0)
     {
         var kayıt = constantService.Add(constant);
         TempData["Mesaj"] = kayıt.BasariliMi ? "Kayıt Eklendi." : kayıt.Mesaj;
         return(RedirectToAction("Create", "Constant"));
     }
     else
     {
         var kayıt = constantService.Get(x => x.Id == constant.Id).Data;
         constant.LogoUrl = kayıt.LogoUrl;
         constantService.Update(constant);
         return(RedirectToAction("Index", "Constant"));
     }
 }
        public IActionResult Post([FromBody] Constant data)
        {
            var createdConstant = service.Add(data);

            return(CreatedAtAction("Get", new { id = createdConstant.Data.Id }, createdConstant));
        }