At a Glance; Contents; About the Author; About the Technical Reviewer; Introduction; Chapter 1: MVVM as Design Pattern; Three-Tier Application Architecture; Model-View-Controller (MVC); Model-View-Presenter (MVP); Model-View-ViewModel (MVVM); Summary; References; Chapter 2: Setting Up the POSApp; POSApp Forms; Mixing Business and Presentation; Declaration of Classes; The Database Unit; Total Sales; The Main Form; The Sales Invoice Form; Retrieving Data; Updating the Form; Summary; References; Chapter 3: MVVM as Design Philosophy; The View of the MainScreen

The Model of the MainScreenThe ViewModel of the MainScreen; Creating the Classes; How the Code Works; Creating the ViewModel and the Model Outside the Main Form; Notes About the Code; How We Converted MainScreen; Summary; Chapter 4: Two-Way Communication; The Provider-Subscriber (ProSu) Framework; Two-Way Communication (Revisited); Making the Code More Efficient; Summary; References; Chapter 5: Converting the InvoiceForm; The View of the InvoiceForm; The Model of the InvoiceForm; The ViewModel of the InvoiceForm; Retrieving the Labels from the ViewModel; Setting Up the Invoice Form

Disabling and Hiding ElementsGetting the Customer and Items Lists; Summary; Chapter 6: User Interaction; Selecting a Customer; Adding an Item to the Invoice; The Model; The ViewModel; The View; Summary; Chapter 7: Input Validation; Checking Inputs; Bits and Pieces; Deleting an Item from the Invoice; Applying Discounts to the Invoices; Printing the Invoice and Closing the Form; Summary; Index