Using RedirectToAction with custom type parameter

Question

asp.net mvc 2

I have this action in Identity controller

public ActionResult Details(string id, MessageUi message)
{

And I'm trying to redirect to this action from another controller, but I don't know how should I pass the message parameter

I was trying with

    var id = "someidvalue"
    var message = new MessageUi("somevalue");
    return RedirectToAction("Details", "Identity", new { id, message});
}

but message parameter is null

Answer 1

That's normal. You cannot pass complex objects in urls when redirecting and that's the reason why the MessageUi object is not received. Only scalar properties which will be translated into &-separated key/value pairs in the url.

---

One possibility would be to pass all the simple properties of this object so that the default model binder can reconstruct it at the target location:

var id = "someidvalue"
var message = new MessageUi("somevalue");
return RedirectToAction("Details", "Identity", new { 
    id = id, 
    MessageProp1 = message.MessageProp1,
    MessageProp2 = message.MessageProp2,
    MessageProp3 = message.MessageProp3,
});

---

You could also pass only a message id:

var id = "someidvalue";
return RedirectToAction("Details", "Identity", new { 
    id = id, 
    messageId = "somevalue"
});

and have the message object being reconstructed in the details action using this id:

public ActionResult Details(string id, string messageId)
{
    var message = new MessageUi(messageId);
    ...
}

and this job could be greatly done by a custom model binder for the MessageUi type.

---

Another possibility would be to use TempData or Session:

var id = "someidvalue";
TempData["message"] = new MessageUi("somevalue");
return RedirectToAction("Details", "Identity", new { id });

and then inside the Details action:

var message = TempData["message"] as MessageUi;