WPF带有MVVM的多个窗口

Question

What is the common\\best practice when working with multiple windows with MVVM? I have one window with a button, when clicking on the button I want to open a second window and close the first window. How can I do that with MVVM? should I have a MainViewModel instance for each window? or should I have only one instance of the MainViewModel that all the windows will use?

Thanks!

Answer 1

Caliburn.Micro suggest a concept called Conductors that handles this situation pretty well.

you can manage the lifetime of a screen or multiple screens by making your MainViewModel inherit from Conductor<T>.Collection.OneActive or Conductor<T>.Collection.AllActive depending how many active windows can be shown at once.

It hold Items which is the currently conducted items and provides OnActivate and OnDeactive methods where you can implement your on activation and deactivation logic.

This is a very strong framework, but it will require you to incorporate Caliburn.Micro in your project and bootstrapping it which may be kind of a hassle if you are working with a different MVVM framework. However you can still implement this concept or look for similar implementations in other frameworks.

Answer 2

Try to use "Frame" and "Pages" inside it. I think that is the best solution for you.

Answer 3

You have two options:

1. open a new View by using the code-behind (I do not like this solution, since it is not very MVVM compliant)
2. you can use Dependency Injection

I do not know if you are using a specific MVVM framework (like Caliburn.Micro, MVVM-light and so on), so if you are looking for a generic solution which uses Dependency Injection, you can find tons of good articles.

I suggest you to read these ones:

1. WPF Master Details MVVM Application
2. Showing Dialogs When Using the MVVM Pattern
3. Cinch V2: Version 2 of my Cinch MVVM framework: Part 1 of n - just the "MEFedMVVM and ViewModel/Service Resolution" chapter