WPF

Adrian Alexander wrote:

The view doesn't exist during unit testing.

MessageBoxButtons result = ViewModelBase.GetService<IDialogService>().ShowMessageBox(...);

switch (result)
{
}

Adrian Alexander wrote:

As you just pointed out, making the lamdas into methods would then mean you can
directly call them for testing, so I don't see any problem there.

Adrian Alexander wrote:

In fact, those "lambdas" are ICommands like any other in the VM.

Adrian Alexander wrote:

In any case, the technique I suggest could easily be adjusted to work with a
switch statement if you like doing it that way.

Adrian Alexander wrote:

I prefer using binding (which everyone uses in the WPF apps anyway) and you're
determined to use a service locator (which I don't see any need to introduce
into my code).

SledgeHammer01 wrote:

ICommands are only created when you need to invoke some operation from the UI.

Adrian Alexander wrote:

That's exactly correct, and that's what's happening in this case. Just as you
bind an ICommand to Button.Command, using my approach you associate an ICommand
with a button on the message box.

class MyClass : ViewModelBase
{
   private IDialogService _dlgService = null;

   public MyClass()
   {
      _dlgService = ViewModelBase.ServiceLocator.GetService<IDialogService>();
   }
}

class MyClass : ViewModelBase
{
   private IDialogService _dlgService = null;

   public MyClass(IDialogService dlgService)
   {
      _dlgService = dlgService;
   }
}