Redirect to action with parameters always null in mvc - asp.net-mvc-4

Question

When I tried redirect to action, the parameter is always null when I received ? I don't know why this happening like these.
ActionResult action1() {
if(ModelState.IsValid) {
// Here user object with updated data
redirectToAction("action2", new{ user = user });
}
return view(Model);
}
ActionResult action2(User user) {
// user object here always null when control comes to action 2
return view(user);
}
And with this I've another doubt. when I accessed action with route, i can get values only by RouteData.Values["Id"]. the values routed doesn't send to parameter.
<a href="#Url.RouteUrl("RouteToAction", new { Id = "454" }> </a>
Here Am I miss any configure ? or anything I miss.
ActionResult tempAction(Id) {
// Here Id always null or empty..
// I can get data only by RouteData.Values["Id"]
}

Answer 1

You cannot pass complex objects in an url like that. You will have to send its constituent parts:
public ActionResult Action1()
{
if (ModelState.IsValid)
{
// Here user object with updated data
return RedirectToAction("action2", new {
id = user.Id,
firstName = user.FirstName,
lastName = user.LastName,
...
});
}
return view(Model);
}
Also notice that I have added the return RedirectToAction instead of only calling RedirectToAction as shown in your code.
But a much better approach is to send only the id of the user:
public ActionResult Action1()
{
if (ModelState.IsValid)
{
// Here user object with updated data
return RedirectToAction("action2", new {
id = user.Id,
});
}
return view(Model);
}
and in your target action use this id to retrieve the user from wherever this user is stored (could be database or something):
public ActionResult Action2(int id)
{
User user = GetUserFromSomeWhere(id);
return view(user);
}
Some alternative approaches (but one I don't recommend or use) is to persist the object in TempData:
public ActionResult Action1()
{
if(ModelState.IsValid)
{
TempData["user"] = user;
// Here user object with updated data
return RedirectToAction("action2");
}
return view(Model);
}
and in your target action:
public ActionResult Action2()
{
User user = (User)TempData["user"];
return View(user);
}