获取URL参数的部分视图

http://localhost:50383/register/UserVerify?returnUrl=http%3A%2F%2Flocalhost%3A50383%2Fregister%2Forganization.

UserVerify视图有一个部分视图控件LogonControl。

<% Html.RenderPartial("LogonControl"); %>

 public ActionResult LogonControl(string returnUrl)
        {
            return View();
        }

        [HttpPost]
        public ActionResult LogonControl(LogOnModel model,string returnUrl)
        {
            if (!String.IsNullOrEmpty(returnUrl))
            {
                return Redirect(returnUrl);
            }
            else
            {
                return RedirectToAction("Index", "Public");
            }      
        }

当我测试时,returnUrl没有设置,它是空的。关于如何将returnUrl转到部分视图有什么想法吗?