In this article I am going to add commanding to the earlier post http://www.c-sharpcorner.com/UploadFile/Mahadesh/8807/.

Lets take a copy of the code created in the previous article . We would be doing some modifications to add the Commanding.

Lets start with the PeopleViewModel.cs

We need to add a new class say UpdatePersonCommand. I would place this class in the PeopleViewModel.cs.

public class UpdatePersonCommand : ICommand
 {
public bool CanExecute(object parameter)
{
if (parameter != null)
{
CanExecuteChanged.Invoke(parameter, new EventArgs());
}
return true;
}

public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
// We have some work to do here
}
}

Let me also add my command:

public ICommand UpdateVM
{
get
 {
return new UpdatePersonCommand();
}
}

Let me now modify the MainPage.xaml.cs.

I will change the Button_Click handler as shown below:

private void Button_Click(object sender, RoutedEventArgs e)
{
this.ViewModel.UpdateVM.Execute(this.Resources["ViewModel"] as PeopleViewModel);
}

What I do is just call the Execute on the Update Command which would modify my ViewModel.

As can be seen I pass the PageViewModel Instance in the execute method.

Nothing changes in the xaml code.

Just call the UpdatePerson in the Execute of the UpdatePersonCommand class.

public void Execute(object parameter)
{
(parameter as PeopleViewModel).UpdatePerson();
}

Run the project. It works the same way.

Thanks. Happy coding.