It's now time to build the user interface screens; we are going to start by building the view-models. Inside the FileStorage.Portable project, add a new folder called ViewModels, add a new file called MainPageViewModel.cs, and implement the following:

public class MainPageViewModel : ViewModelBase
  {
     #region Private Properties
     private string _descriptionMessage = "Welcome to the Filing Room";
     private string _FilesTitle = "Files";
     private string _exitTitle = "Exit";
     private ICommand _locationCommand;
     private ICommand _exitCommand;
     private ISQLiteStorage _storage;
     #endregion
  }

We include the ISQLiteStorage object in this view-model because we will be creating the database tables when this view-model is created. Don't forget we need to implement the public properties for all private properties; the following are two properties to get you started:

#region Public Properties
public ICommand LocationCommand
  {
    get
     {
...