Visual Basic 201 - Object Oriented Programming and Design Patterns

Understanding Classes and Objects

This lengthy video explains the parts of a class, which is the basic building block used in every VB.NET application. Classes have properties and methods, contructors and destructors, and methods can be overloaded. This video starts you out at the very basics of all these concepts, which are more thoroughly explained in future videos in this series. Also, I build a small application that uses a class and step through the code to demonstrate the order of events when creating an instance of an object for your applications.

Creating Methods

This video goes into more depth about methods, such as what private and public means, overloading methods, and returning values or creating void methods that return nothing.

Understanding Overloaded Methods

This video demonstrates the use of overloaded methods with a small application. The code is stepped through and thoroughly explained.

Constructors and Destructors

Constructors are the rough equivilent of the Initialize event in VB6 classes, but with the added ability to be overloaded. The is no true equivilent to the Terminate event in VB6 classes, which is deterministic ... in other words, in VB6 you know exactly when the object was being unloaded from memory. However, due to garbage collection in VB.NET, finalization in in-deterministic ... you don't REALLY know when an object is being unloaded from memory, therefore you must adopt new practices for object "clean-up". This video discusses constructors and the finalize method in classes, as well as a common convention to be used before setting a object reference to nothing.

Creating and Referencing Assemblies

This video demonstrates how to create a class library, which is an assembly compiled into a DLL that can be referenced from other projects. It is the rough equivilent to creating a COM+ component in VB6. Obviously, there is a significant difference in COM+ and .NET, but the idea for our purposes here is that you can have a component that contains classes for use in other projects. This video demonstrates how to create such a class library, then use it from a consuming application. Explains the Add Reference dialog.

Understanding Namespaces

Namespaces allow you to remove ambiguity between components that may have the same classes and same file name. This video shows how to set the root namespace, as well as how to create sub-level namespaces. Additionally, it shows what happens when you use the Imports keyword, and most importantly what happens when there is a naming conflict.

Inheritance Basics

Inheritance was available in VB6 in a limited form (i.e., interface inheritance), but is more fully realized in VB.NET (i.e., implementation or "code" inheritance). This video shows the basics of how inheritance works, and sets the stage for many future videos on this vital topic.

Inheritance Basics

Inheritance Basics

Polymorphism Basics

Polymorphism Basics

Favor Composition Over Inheritance

Favor Composition Over Inheritance

Find What Varies and Encapsulate It

Find What Varies and Encapsulate It

Strategy Design Pattern

Strategy Design Pattern

Interface Basics

Interface Basics

Program to Interfaces and not to Implementations

Program to Interfaces and not to Implementations

Abstract Factory Design Pattern

Abstract Factory Design Pattern

More About Scoping and Interfaces

More About Scoping and Interfaces

GRASP: High Cohesion

GRASP: High Cohesion

GRASP: Low Coupling

GRASP: Low Coupling

GRASP: Controller

GRASP: Controller

GRASP: Expert

GRASP: Expert

GRASP: Creator

GRASP: Creator

GRASP: Pure Fabrication

GRASP: Pure Fabrication

GRASP: Indirection

GRASP: Indirection

GRASP: Dont Talk to Strangers

GRASP: Dont Talk to Strangers

Model-View Seperation Pattern

Model-View Seperation Pattern

GoF Creation Patterns: Singleton

GoF Creation Patterns: Singleton

GoF Creation Patterns: Builder

GoF Creation Patterns: Builder

GoF Creation Patterns: Prototype

GoF Creation Patterns: Prototype

GoF Structural Patterns: Adapter

GoF Structural Patterns: Adapter

GoF Structural Patterns: Bridge

GoF Structural Patterns: Bridge

GoF Structural Patterns: Composite

GoF Structural Patterns: Composite

GoF Structural Patterns: Decorator

GoF Structural Patterns: Decorator

GoF Structural Patterns: Facade

GoF Structural Patterns: Facade

GoF Structural Patterns: Flyweight

GoF Structural Patterns: Flyweight

GoF Behavioral Patterns: Chain of Responsibility

GoF Behavioral Patterns: Chain of Responsibility

GoF Structural Patterns: Proxy

GoF Structural Patterns: Proxy

GoF Behavioral Patterns: Command

GoF Behavioral Patterns: Command

GoF Behavioral Patterns: Interpreter

GoF Behavioral Patterns: Interpreter

GoF Behavioral Patterns: Iterator

GoF Behavioral Patterns: Iterator

VB.NET Delegate Basics

Delegates are object oriented function pointers allowing you to handle callbacks and events.

XML Object Serialization

Demonstrates how to serialize objects to an XML file, then how to deserialize the XML back to a new instance of an object.