Implementing the viewmodel

Now let's move on to viewmodel. Add a new C# class file to the ViewModels folder and name it InstallViewModel. Add the following code:

using CustomBA.Models;
using Microsoft.Practices.Prism.Commands;
using Microsoft.Practices.Prism.ViewModel;
using Microsoft.Tools.WindowsInstallerXml.Bootstrapper;
using System;
using System.Windows.Input;

namespace CustomBA.ViewModels
{
    public class InstallViewModel : NotificationObject
    {
        public enum InstallState
        {
            Initializing,
            Present,
            NotPresent,
            Applying,
            Cancelled
        }

        private InstallState state;
        private string message;

        private BootstrapperApplicationModel model;

        public ICommand InstallCommand { get; private set; }

        public ICommand UninstallCommand { get; private set; }

        public ICommand CancelCommand { get; private set; }

        public string Message
        {
            get
     ...