What is difference between View and Page in Asp.net core 2?

Question

I am new in Asp.net core 2. One of the new things in Asp.net core 2 are pages. But I can't figure it out

1. What is difference between page and view?
2. What are the benefits of pages versus views?
3. In what cases should the page be used?
4. Can I use both at the same time?

Answer 1

Really, your question is what's the difference between a Razor Page and traditional MVC. Both utilize Razor views. A Razor Page is self-contained (sort of). It has a code-behind like a Web Form, so technically you'd have a cshtml and a cshtml.cs file, the latter of which would act as both your controller and your model. Whereas, with traditional MVC, you'd have separate FooController, FooViewModel, and Foo.cshtml. Aside from some slight functional differences (such as having to use convention-based "actions" like OnGetAsync, OnPostAsync, etc. with Razor Pages) that's pretty much it.

The chief benefit to Razor Pages, as I see it, is its self-contained nature. All the code regarding a particular piece of functionality is essentially all in one place. However, the downside to this is that it can make code reuse difficult or at least not as intuitive in some places. Personally, I think the clear division of responsibilities offered by MVC is the more ideal approach and its also less "magical". One of the marketing touchpoints of Razor Pages is that it's stupidly easy. That may be true, but it owes its "ease" to abstracting away things web developers should actually be cognizant of, and that can be dangerous. If you don't actually understand how something works, you won't know if you're doing things right.

I'm biased, but to honestly answer "When should Razor Pages be used?", I would say never. I don't like the mixing of responsibilities, all the "magic", etc. Since they were introduced the number of ASP.NET Core questions here have skyrocketed and the majority of the Razor Pages questions are about things that are either obvious or at least more intuitive with MVC. That said, if you are going to use them, they make the most sense on CRUD type stuff - things that don't have a lot of functionality and are fairly straight-forward and/or repetitive.

Finally, yes you can freely mix and match Razor Pages and MVC. However, it should be noted because it's not obvious to everyone: Razor Pages only work as Razor Pages when used as Razor Pages. In other words, if you create a view with a code-behind (a Razor Page) and then use that view as a return from an MVC action, a partial, etc., the code-behind isn't actually utilized, just the "view" portion. Actually, to be more accurate, it is "used" but only to provide the model for the view in a general sense, since the view uses the Page in the code-behind as its model. However, this won't actually be "active", in the sense that page actions won't be hit, things likely won't get initialized properly, etc.