ASP.net MVC - One ViewModel per View or per Action?

Question

Is it a better idea to have a single ViewModel per view or one per controller action?

Example:

public ProjectController : Controller
{
    public Act         


        

Answer 1

I follow this approach for basic forms:

• One view model for the GET
• One view model for the POST

The GET model inherits the POST model.

I will often pass a domain object to the GET model's constructor, and do 2 things with it:

1. Populate the POST model properties with data from the domain object.
2. Encapsulate the domain object as a local variable in the GET model. I use this for displaying some (read-only) data from the domain object. Saves a bit of effort. Some people will tell you not to do this.