在C＃WPF桌面应用程序中将ViewModel的属性分配给另一个ViewModel的属性

Question

I'm developing a C# WPF MVVM app. I'm new to to MVVM and not using any toolkits/libraries, just an ActionCommand class which implements the ICommand interface and a BaseINPC class which implements INotifyPropertyChanged (my ViewModels derive from this class).

My Model has a DataSet class with a string InputPath property (the location of the dataset file).

In my MainView , I have a Menu on the top which is a View of it's own ( MenuView ), implemented using a UserControl which has it's DataContext set to it's corresponding MenuViewModel . Each menu item is bound to an ActionCommand which does basic IO operations, such as OpenFileDialogs for loading files etc. The MenuViewModel has a SelectedPath property for holding the location of the file.

My problem is this: when I select a file using my MenuView (ie setting the SelectedPath property in my MenuViewModel ), I also want it to set DataSet.InputPath to SelectedPath . My DataSet class is however instantiated in my MainViewModel , not the MenuViewModel , which is pretty much where I'm stuck.

Is my approach correct? If so, how can DataSet.InputPath (in MainViewModel ) be set to SelectedPath (of MenuViewModel )?

Answer 1

If you insist on not using an MVVM framework you need to write your own Message Bus implementation...

Otherwise, virtually all MVVM frameworks use Message Bus for this type of inter-VM communication so picking a nice noob friendly MVVM framework (I'd recommend Simple MVVM Toolkit or MVVM Light) and utilizing its Message Bus instead of reinventing the wheel and writing your own MB is the way to go.