详细动作如何运作

Question

I have a controller in which i have some actions. One of these, is the Detail action. Here:

public ActionResult Details(int id) {
    Type x = ReadFromSomewhere(id);
    return View(x);
} 

I have another action , that after updating the Type x object , it will return the same object again to the Detail action. So:

[HttpPost]
public ActionResult Update(Type y)
{
    Some works here...

    return View("Details", y);
}

As you can see i don't pass the id to the return View("Details", y); but everythigs work. Why ? I mean, i should return something like this:

return View("Details", y.Id);

But the View() method accepts only object after the name of the view. So, What kind of magic is this?

Thank you

Answer 1

There is a very simple reason for this. The View() method that you are calling is looking for the view name as the first parameter, and the model object as the second.

In order to not have a generic overload of that method, the type that they are looking for is object . Since that is the base type of EVERY type in .NET, you are able to supply any type as the parameter.

You can set your method call up like that, however you would get a run time exception when the Razor engine tries to render your page and it has a different model type than it is expecting.