Disable WPF buttons during longer running process, the MVVM way

Question

I have a WPF/MVVM app, which consists of one window with a few buttons.
Each of the buttons triggers a call to an external device (an USB missile launcher), which takes

Answer 1

Ok the CanExecute method will not work because the click will immediately put you into your long-running task.
So here's how I would do it:

1. Make your view model implement INotifyPropertyChanged

2. Add a property called something like:

   public bool IsBusy
   {
       get
       {
           return this.isBusy;
       }
       set
       { 
           this.isBusy = value;
           RaisePropertyChanged("IsBusy");
       }
   }
   

3. Bind your buttons to this property in this manner:

4. In your ShowMessage/CallExternal device methods add the line

   IsBusy = true;
   

Should do the trick