require 'xamltools.rb'
 
class MyCommand
  include System::Windows::Input::ICommand
  def add_CanExecuteChanged(h)
    @change_handlers << h
  end
  def remove_CanExecuteChanged(h)
    @change_handlers.remove(h)
  end
  def can_execute(args)
    @can_execute
  end
  def execute(arg)
    puts "I'm being commanded"
    @can_execute = false
    @change_handlers.each{ |h| h.Invoke(self, System::EventArgs.new) }
  end
  def initialize
    @change_handlers = []
    @can_execute = true
  end
end
class ViewModel
  attr :my_command, true
  def initialize
    @my_command = MyCommand.new
  end
end
 
view = XamlTools::Xaml.window( :Width => 450, :SizeToContent => :Height) do |w|
  w.Button( :Content => "Click Me!", :Command => "{Binding Path=my_command}")
end
 
view.data_context = ViewModel.new
 
System::Windows::Application.new.run(view)