ASP.Net MVC: regarding RedirectToAction function

Question

suppose i have two action in controller called login

 

public ActionResult Login()
{
    return View();
}

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Login(UserProfile objUser)
{
    if (ModelState.IsValid)
    {
    using(DB_Entities db = new DB_Entities())
    {
        var obj = db.UserProfiles.Where(a => a.UserName.Equals(objUser.UserName) && a.Password.Equals(objUser.Password)).FirstOrDefault();
        if (obj != null)
        {
        Session["UserID"] = obj.UserId.ToString();
        Session["UserName"] = obj.UserName.ToString();
        return RedirectToAction("UserDashBoard");
        }
    }
    }
    return View(objUser);
}

 when we write return RedirectToAction("Login");  then how asp.net mvc understand that we are thinking about login function which uisng get http verb login not post http verb login ?

anyone can explian it ?

 

how we can redirect to action which is based on post http verb ?

what will be the syntax if we need to redirect to action with http verb if we use RedirectToAction function  ?

 

thanks