Book Image

.NET Design Patterns

By : Praseed Pai, Shine Xavier
Book Image

.NET Design Patterns

By: Praseed Pai, Shine Xavier

Overview of this book

Knowing about design patterns enables developers to improve their code base, promoting code reuse and making their design more robust. This book focuses on the practical aspects of programming in .NET. You will learn about some of the relevant design patterns (and their application) that are most widely used. We start with classic object-oriented programming (OOP) techniques, evaluate parallel programming and concurrency models, enhance implementations by mixing OOP and functional programming, and finally to the reactive programming model where functional programming and OOP are used in synergy to write better code. Throughout this book, we’ll show you how to deal with architecture/design techniques, GoF patterns, relevant patterns from other catalogs, functional programming, and reactive programming techniques. After reading this book, you will be able to convincingly leverage these design patterns (factory pattern, builder pattern, prototype pattern, adapter pattern, facade pattern, decorator pattern, observer pattern and so on) for your programs. You will also be able to write fluid functional code in .NET that would leverage concurrency and parallelism!
Table of Contents (22 chapters)
.NET Design Patterns
Credits
Foreword
About the Authors
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

The graph plotter application


The graph plotter application is a simple WPF application with a canvas and a textbox in the frame. The following image gives a snapshot of the screen after the screen has rendered the result of an expression:

The WPF canvas gets a notification whenever there is a change in the expression textbox. If the expression in the textbox is valid, the graph will be plotted as shown in the preceding image. We will deal with the nuances of implementing an expression evaluation engine in the following sections. The following code snippet shows how the change in text gets handled:

    public override void  
    Observer_ExpressionChangedEvent( string expression) 
    { 
      MainWindow mw = this._ctrl as MainWindow; 
      mw.Expr = expression; 
      ExpressionBuilder builder = new  
      ExpressionBuilder(expression); 
      Exp expr_tree = builder.GetExpression(); 
 
      if ( expr_tree != null ) 
      mw.Render(...