Design Patterns in .NET

I was recently messaged by someone on LinkedIn, and since my response seemed full enough, I thought I'd share. Question I see that you also program in VBA but you have made the jump to .NET. Unfortunately, I have found C#/Excel coding to be quite slow and just wanted to hear about your experiences. Responses Slow? It depends on what you mean. Honest, I have had to make the pitch when building apps that it should be in .NET rather than VBA for speed. One particular app had a form that needed to fill about 20 dropdowns on load, so using async operations was essential. That same app, while executing one SQL statement in the foreground, also executed 2 background statements that filled panels. It wouldn't have performed well if done in VBA. If you mean that it takes longer, then yes, but that is a necessity for good code anyway. If you only need a local operation, non-threaded, that doesn't need to be used across the enterprise, VBA can make sense, but with .NET comes n...

My responses in a NY Times comment section for the book, Coders: The Making of a New Tribe and the Remaking of the World by Clive Thompson : #1 - Link Although I've been a software developer for 15 years, and for longer alternating between a project manager, team lead, or analyst, mostly in finance, and now with a cancer center, I found it funny that you blame the people doing the coding for not seeing the harm it could cause. First, most scientific advancement has dark elements, and it is usually not the science but how it is used and sold by business people that is the problem. This leads to the second problem, in that it is not coding that is in itself problematic, but specifically how technology is harnessed to sell. It is normal and desirable to track users, to log actions, to collect telemetry, so as to monitor systems, respond to errors, and to develop new features, but that normal engineering practice has been used to surveil users for the purpose of selling. Blaming ...

Responding to a question on HashNode, Developers who practise algorithms are better at software development than people who just do development. Is it true? , I wrote the following: My feeling is that algorithms help make one a better programmer, but that is likely true of many coding concepts. I did not have algorithms as an undergraduate, so my knowledge is acquired through reading and practice, but after reading and applying Algorithm's in a Nutshell, I felt the quality of my work improved. That said, my development work increased more after understanding Design Patterns, or after consuming books on database design.  Since many types of knowledge improve developing and architecting abilities, one has to consider how it helps and to what degree. Algorithms are coding-in-the-small, often narrowly focused solutions, but which can have a great impact at scale. For many applications, a focus on algorithms would be overkill as data sets and requirements do not require it. In this ...

Thinking Architecturally by Nathaniel Schutta My rating: 4 of 5 stars An overview of architectural decisions, the politics and persuasion involved, and the needs to balance competing measures and attributes. A fairly easy read, but full of great suggestions, and, for many, reminders of how to handle being a senior developer or architect. View all my reviews

This is a report a short review I provided for G2 regarding TFS : What do you like best? If you use Visual Studio for development, TFS, or its online equivalent VSTS, you can have a fairly seamless end-to-end integration. Out of the box, it provides code management, testing, work hierarchy in agile formats, automated build, and deployment. What do you dislike? Branching and merging can be a bit painful, in that it needs to be planned, and is not natively part of the process. Code review also needs to be planned and only recently has it become part of the process. Recommendations to others considering the product My only concern regarding TFS and VSTS is that Microsoft itself recommends using Git. What business problems are you solving with the product? What benefits have you realized? In my current role, I've joined a shop that has application development as secondary to their role of desktop OS and app deployment/maintenance, so their code management practi...

Responding to How do you deal with making sure your use of new technology is correct and free from code-smells, security issues, etc.? : Issues can be dealt with in several ways. Understanding what makes high-quality, maintainable code would be first, so knowledge of best practices regarding OOP, SOLID, design patterns, API design, etc. is important. Depending on what you mean by security, best practices in those regarding transfer protocols, coding styles, validation, storage, etc. are equally something one can learn. Planning your work is useful, as a well thought out design is easier to implement, or at least will avoid future problems, than when you are just 'winging it'. Diagramming and project plans can be useful at this stage. Self-management is part of this, so using boards and epic/stories/tasks to track work is important, and there are free tools like Visual Studio Team Services (VSTS) or Trello to help. Requirements gathering will matter so documentation and c...

I have been toying with the idea of migrating one of my sites to a better host - it was supported by Yahoo and now AAbaco - and implementing some newer technologies. Among products I have used at work or are working with peripherally, I am considering using ASP.NET MVC, Entity Framework, ReSTful API's, NoSQL, and Azure-hosted databases - it is currently a mixture of very low-end PHP, HTML5/CSS3, light Javascript, and MySQL - so I decided to write up an architectural diagram - it looks like any standard architecture, with maybe a few additional elements - to help with the planning:

I recently came across a new way of implementing the Singleton pattern, detailed in this article . The article details, (1) the use of the volatile keyword, and (2) a new simpler way of implementing a Singleton by using the Lazy<T> class , something that was not available when I first wrote the section on the Singleton .

Design Patterns: Elements of Reusable Object-Oriented Software by Erich Gamma My rating: 5 of 5 stars Depending on on how you think of programming, this book could be incredibly insightful, or horribly abstract and impractical. Since I prefer and tend to think in patterns and abstractions, I found this book close to my heart. It uses a variety of languages for examples, so a willingness to explore concepts, not practical solutions, is essential. View all my reviews

This is an example of the Decorator pattern, in this case a decorator for ObservableCollection.  Working with WPF and ObservableCollection using threads, one will run into the problem whereby the ObservableCollection cannot be updated from outside the owning thread; Delegates and Invoke will not work. A solution is to contain and expand the class, as is done in this example on michIG's Blog . This linked file contains the original code in C#, as well as the same code converted to VB.NET. Salient Characteristic(s) Sets an internal pointer to the decorated object, sending method calls and property actions to the internal object Extends the object by wrapping it and adding some aspect handled by the decorator Code using System; using System.Collections.ObjectModel; using System.Windows.Threading; using System.Collections.Specialized; using System.ComponentModel; namespace DesignPatterns {     /// <summary>       /// This class is an...

A implementation of the composite pattern similar to a class that would be used for constructing a binary search tree.  Better, more detailed implementations are known as red-black or AVL trees. Salient Characteristic(s) Reduces complexity by treating objects consistently, as opposed to having different methods and properties for each collection Any modification method of a collection would nbe the same as modifying the container Code namespace DesignPatterns {     /// <summary>     /// An example of composite that might be used in a binary tree     /// In this case, the tree node is composed of tree nodes     /// Any modification method of a node, would be the same as modifying the node itself     /// </summary>     public class TreeNode      {         private int _Value;         public int Value         {   ...

A bare-bones, generic implementation of the bridge pattern, using inheritance, polymorphism, and abstraction.  Salient Characteristic(s) Decouple classes, allowing them to vary independently Useful when frequent changes are made to classes Code namespace DesignPatterns {     /// <summary>     /// The implementor: the abstract class, and concrete implementation of one side of the relation     /// </summary>      public interface IBridgeAbstraction     {         void Build();     }          abstract class BridgeAbstraction : IBridgeAbstraction     {         public abstract void Build();     }     class ConcreteBridge1 : BridgeAbstraction     {         public override void Build()         {         }   ...

A friend amusingly posted on Facebook a retro photograph of four (4) 'designers' around a cat, with the caption alluding to designing hats for cats, and so I decided to make, somewhat incongruously, an abstract cat factory, which varies by the location of the cat..   Salient Characteristic(s) Classes derived from abstract types Class creates derived (concrete) classes based on type required Code namespace DesignPatterns {     public enum Location     {         Kitchen,         Bedroom,         LivingRoom     }     public enum Amusements     {         String,         Mouse,         Food,         Sleep     }          public abstract class Feline     {         public abstract Feline HereKittyKitty...

This is code possible through .NET, in that it bridges across to COM for automation in VBA.  This concept can be extended to work for many other COM-based applications.  This code allows the add-in to expose internal .NET-coded procedures to Excel COM, extending the use of the .NET code. Salient Characteristic(s) Handle interface between different, incompatible systems The interface is required because COM is interface-based Other code elements are required for this to work properly Registering the DLL Creating the AdapterForVBA class on startup Code using System; using System.Runtime.InteropServices; namespace DesignPatterns {     /// <summary>     /// Interace to expose VSTO/COM obects for COM and Excel     /// Used by class below     /// </summary>     [ComVisible(true)]     [Guid("B523844E-1A41-4118-A0F0-FDFA7BCD77C9")]     [InterfaceType(ComInterfaceType.InterfaceIs...

This is derived from actual code of mine, and elements of this sample combine the Facade pattern with the Publisher (Observer) pattern.  The primary class, based on the ISubscriber interface, is fairly complicated to use, requiring delegates, threading, and asynchronous callbacks.  The facade, based on ISubscriberFacade, encapsulates all the methods required to work with the Windows Communication Foundation (WCF) service , handling threading, delegate creation, and asynchronous callbacks internally, so that that the clients only need to create the object.  I wrote the encapsulating client to ease the adoption of the WCF service for legacy clients, seeing that the code complexity was likely a hurdle. Salient Characteristic(s) Reduces or hides complexities to other clients or systems Simplified interaction between systems and/or types Note DispatchingObservableCollection is based on ObservableCollection commonly used in Windows Presentation Foun...

A fairly simple example of the multiton pattern, with a private constructor, and a tracker for created objects, the name being an integer identifier. Salient Chacteristic(s) A private keyed list for tracking objects A private constructor Named objects Code using System.Collections.Generic; using System.Linq; namespace DesignPatterns {     public class Multiton     {         //read-only dictionary to track multitons         private static IDictionary<int, Multiton> _Tracker = new Dictionary<int, Multiton> { };         private Multiton()         {         }         public static Multiton GetInstance(int key)         {             //value to return             Multiton item = null;              ...

The Singleton design pattern seems generally frowned upon, except for use in logging classes.  Below are several variants of the Singleton design pattern, of which, only the thread-safe version merits attention: Salient Chacteristic(s) A private constructor Static variable for self-tracking Three (3) variants Eager Lazy Thread-safe (Double-checked Locking) Code namespace DesignPatterns {     //double-checked locking singleton     //required for threaded environments     public class DoubleCheckingSingleton     {         private static volatile DoubleCheckingSingleton _Instance = null;         private static object _SyncRoot = new object();              //Private constructor prevents instantiation from other classes         private DoubleCheckingSingleton()         {        ...

Whereas ICloneable will be used to return a shallow copy, the data object's attribute Serializable enables creation of a deep copy of the data object, instead of a reference: Salient Chacteristic(s) Shallow copies use the native IConeable Interface Deep copies requires use of creation of new objects, not references For this, use of Serializable attribute to create a new copies Code using System; using System.IO; using Serialization = System.Runtime.Serialization; namespace DesignPatterns {     /// <summary>     /// A serializable data object, the attribute     ///  necessary for simple form of deep copy     /// </summary>     [Serializable]     public class SerializableDataObject      {         public SerializableDataObject(int objectId)         {         }         private int _Id; ...