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What this book coversChapter 1, A Smarter Way of Working with WPF, introduces the Model, View, View Model(MVVM) software architectural pattern and the benefits of using it with WPF.Chapter 2, Debugging WPF Applications, provides essential tips on various methods ofdebugging WPF applications, ensuring the ability to iron out any problems that may occur.Chapter 3, Writing Custom Application Frameworks, introduces the indispensable conceptof application frameworks, with early examples that will be built upon as the bookprogresses. By the end of the book, you will have a fully functioning Framework with whichto build your applications upon.Chapter 4, Becoming Proficient with Data Binding, demystifies data binding and clearlydemonstrates how to use it in a practical application. A plethora of examples will help you tounderstand which binding syntax to use in any given situation and to be confident that theirbindings will work as expected.Chapter 5, Using The Right Controls for The Job, explains which controls to use inparticular situations and describes the various ways to modify them when required. Itclearly outlines how to customize existing controls and how to create custom controls whenrequired.Chapter 6, Mastering Practical Animations, explains the ins and outs of WPF Animations,detailing lesser known functionality. It concludes with a number of ideas for practicalanimations and continues to build upon the custom application framework.Chapter 7, Creating Visually Stunning User Interfaces, offers advice for getting the mostout of the WPF visuals, while remaining practical, and provides handy tips on makingapplications stand out from the crowd.Chapter 8, Implementing Responsive Data Validation, presents a number of methods ofdata validation to suit every situation and continues to build upon the custom applicationframework. It covers full, partial, instant, and delayed validation and a variety of differentways to display validation errors.Chapter 9, Completing That Great User Experience, provides tips for creating applicationswith a great user experience. Concepts introduced here, such as asynchronous dataaccess and keeping the end users well informed, will substantially improve the existingcustom application framework.Chapter 10, Improving Application Performance, lists a number of ways to increase theperformance of WPF applications from freezing resources to implementing virtualization.Readers that follow these tips and tricks can rest assured that their WPF applications willperform as optimally as they can.Chapter 11, Deploying Your Masterpiece Application, covers the final requirement for allprofessional applications—deployment. It includes the older method of using the WindowsInstaller software, along with the more common and up-to-date method of using ClickOncefunctionality.Chapter 12, What Next?, summarizes what you have learned from this book and suggestswhat you can do with many of your various new skills. It provides you with further ideas onextending the application framework.

What you need for this bookAs with all WPF development, you'll need to have the .NET Framework and a version ofMicrosoft's Visual Studio integrated development environment software installed on yourcomputer.You'll be able to use versions as old as 2010, but in order to use the code in the book thattakes advantage of the latest .NET Framework improvements, you'll need to use one of thenewer versions. Note that any edition of Visual Studio can be used, from the top of the lineEnterprise edition to the free Community (2015) edition.

Who this book is forThis book is for working developers with a basic to moderate level of knowledge aboutWindows Presentation Foundation and for those interested in improving their practical dayto day WPF skills. It will also be of special interest to individuals wanting to know moreabout application architecture and those wanting to improve the look of their userinterfaces.

ConventionsIn this book, you will find a number of text styles that distinguish between different kinds ofinformation. Here are some examples of these styles and an explanation of their meaning.Code words in text, database table names, folder names, filenames, file extensions,pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "There aretwo other useful properties declared by the Grid class."A block of code is set as follows:public string Name{get { return name; }set{if (name ! value){name value;NotifyPropertyChanged("Name");}}}Any command-line input or output is written as follows:System.Windows.Data Error: 17 : Cannot get 'Item[]' value (type'ValidationError') from '(Validation.Errors)' (type'ReadOnlyObservableCollection 1').BindingExpression:Path (Validation.Errors)[0].ErrorContent;DataItem 'TextBox' (Name ''); target element is 'TextBox'(Name '');target property is 'ToolTip' (type entOutOfRangeException:Specified argument was out of the range of valid values.New terms and important words are shown in bold. Words that you see on the screen,for example, in menus or dialog boxes, appear in the text like this: "The Cancel button hasbeen declared in the second row and column."NoteWarnings or important notes appear in a box like this.TipTips and tricks appear like this.

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Chapter 1. A Smarter Way of Working withWPFWhen Windows Presentation Foundation (WPF) was first released as part of the .NETFramework version 3.0 in 2006, it was billed as the future of desktop application GraphicalUser Interface (GUI) languages and supporters claimed that it would put an end to theprevious GUI technology, Windows Forms. However, as time passed, it has fallen far shortof this claim.There are three main reasons that WPF has not taken off as widely as previously expected.The first reason has nothing to do with WPF and stems from the recent push to hosteverything in the cloud and having web interfaces rather than desktop applications. Thesecond reason relates to the very steep learning curve and the very different way ofworking that is required to master WPF.The last reason is that it is not a very efficient language and if a WPF application has lots of'bells and whistles' in, then either the client computers will need to have additional RAMand/or graphics cards installed, or they could face a slow and stuttering user experience.This explains why many companies that make use of WPF today are in the finance industry,where they can afford to upgrade all users' computers to be able to run their applicationsoptimally. This book will aim to make WPF more accessible to the rest of us by providingpractical tips and tricks to help build our real-world applications more easily and moreefficiently.One of the simplest changes with the biggest workflow improvements that we can make toimprove the way we work with WPF is to follow the MVVM software architectural pattern. Itdescribes how we can organize our classes to make our applications more maintainable,testable, and generally simpler to understand. In this chapter, we will take a closer look atthis pattern and discover how it can help us to improve our applications.After discovering what MVVM is and what its benefits are, we'll learn several new ways tocommunicate between the various components in this new environment. We'll then focus onthe physical structure of the code base in a typical MVVM application and investigate avariety of alternative arrangements.What is MVVM and how does it help?Model-View-View Model (MVVM) is a software architectural pattern that was famouslyintroduced by John Gossman on his blog back in 2005 and is now commonly used whendeveloping WPF applications. Its main purpose is to provide a Separation of Concernsbetween the business model, the User Interface (UI), and the business logic. It does thisby dividing them into three distinct types of core components: Models, Views, and ViewModels. Let's take a look at how they are arranged and what each of these componentsrepresent.

As we can see here, the View Models component sits between the Models and the Viewsand provides two-way access to each of them. It should be noted at this point that thereshould be no direct relationship between the Views and Models components and only looseconnections between the other components. Let's now take a closer look at what each ofthese components represent.ModelsUnlike the other MVVM components, the Model constituent comprises of a number ofelements. It encompasses the business data model along with its related validation logicand also the Data Access Layer (DAL), or data repositories, that provide the applicationwith data access and persistence.The data model represents the classes that hold the data in the application. They typicallymirror the columns in the database more or less, although it is common that they arehierarchical in form, and so may require joins to be performed in the data source in order tofully populate them. One alternative would be to design the data model classes to fit therequirements in the UI, but either way, the business logic or validation rules will typicallyreside in the same project as the data model.The code that is used to interface with whatever data persistence technology is used in ourapplication is also included within the Models component of the pattern. Care should betaken when it comes to organizing this component in the code base, as there are a numberof issues to take into consideration. We'll investigate this further in a while, but for now, let'scontinue to find out more about the components in this pattern.View ModelsThe View Models can be explained easily; each View Model provides its associated Viewwith all of the data and functionality that it requires. In some ways, they can be consideredto be similar to the old Windows Forms code behind files, except that they have no directrelationship with the View that they are serving. A better analogy, if you're familiar withMVC, would be that they are similar to the Controllers in the Model-View-Controller (MVC)software architectural pattern. In fact, in his blog, John describes the MVVM pattern asbeing a variation of the MVC pattern.They have two-way connections with the Model component in order to access and updatethe data that the Views require, and often, they transform that data in some way to make iteasier to display and interact with in the UI. They also have two-way connections with theViews through data binding and property change notification. In short, View Models formthe bridge between the Model and the View, which otherwise have no connection to each

other.However, it should be noted that the View Models are only loosely connected to the Viewsand Model components through their data binding and interfaces. The beauty of this patternenables each element to be able to function independently from each other.To maintain the separation between the View Models and the View, we avoid declaring anyproperties of UI-related types in the View Model. We don't want any references to UIrelated DLLs in our View Models project, and so we make use of custom IValueConverterimplementations to convert them to primitive types. For example, we might convertVisibility objects from the UI to plain bool values or convert the selection of somecolored Brush objects to an Enum instance that is safe to use in the View Model.ViewsThe Views define the appearance and layout of the UI. They typically connect with a ViewModel through the use of their DataContext property and display the data that it supplies.They expose the functionality provided by the View Model by connecting its commands tothe UI controls that the users interact with.In general, the basic rule of thumb is that each View has one associated View Model. Thisdoes not mean that a View cannot data bind to more than one data source or that wecannot reuse View Models. It simply means that, in general, if we have a class calledSecurityView, it is more than likely that we'll also have an instance of a class namedSecurityViewModel that will be set as the value of that View's DataContext property.Data bindingOne often overlooked aspect of the MVVM pattern is its requirement for data binding. Wecould not have the full Separation of Concerns without it, as there would be no easy way ofcommunicating between the Views and View Models. The XAML markup, data bindingclasses, and ICommand and INotifyPropertyChanged interfaces are the main tools in WPFthat provide this functionality.The ICommand interface is how commanding is implemented in the .NET Framework. Itprovides behavior that implements and even extends the ever useful Command pattern, inwhich an object encapsulates everything needed to perform an action. Most of the UIcontrols in WPF have Command properties that we can use to connect them to thefunctionality that the commands provide.The INotifyPropertyChanged interface is used to notify binding clients that property valueshave been changed. For example, if we had a User object and it had a Name property, thenour User class would be responsible for raising the PropertyChanged event of theINotifyPropertyChanged interface, specifying the name of the property each time its valuewas changed. We'll look much deeper into all of this later, but now let's see how thearrangement of these components help us.So how does MVVM help?One major benefit of adopting MVVM is that it provides the crucial Separation of Concernsbetween the business model, the UI, and the business logic. This enables us to do severalthings. It frees the View Models from the Models, both the business model and the data

persistence technology. This in turn enables us to reuse the business model in otherapplications and swap out the DAL and replace it with a mock data layer so that we caneffectively test the functionality in our view models without requiring any kind of real dataconnection.It also disconnects the Views from the View logic that they require, as this is provided bythe View Models. This allows us to run each component independently, which has theadvantage of enabling one team to work on designing the Views, while another team workson the View Models. Having parallel work streams enables companies to benefit from vastlyreduced production times.Furthermore, this separation also makes it easier for us to swap the Views for a differenttechnology without needing to change our Model code. We may well need to change som

Windows Platform (Windows, Windows Phone, HoloLens, Xbox One), Xamarin.Forms, WPF, and Silverlight. Also, Alex specializes in cloud-based solutions such as Microsoft Azure. Alex developed training solutions for Microsoft Learning on Windows Phone and Windows 8 and delivers workshops for developers and enterprises. Alex leads the