Design patterns are recurring solutions to software design problems you find again and again in real-world application development. Patterns are about design and interaction of objects, as well as providing a communication platform concerning elegant, reusable solutions to commonly encountered programming challenges.
The Gang of Four (GoF) patterns are generally considered the foundation for all other patterns. They are categorized in three groups: Creational, Structural, and Behavioral. Here you will find information on these important patterns.
To give you a head start, the C# source code is provided in 2 forms: 'structural' and 'real-world'. Structural code uses type names as defined in the pattern definition and UML diagrams. Real-world code provides real-world programming situations where you may use these patterns.
A third form, '.NET optimized' demonstrates design patterns that exploit built-in .NET 4.0 features, such as, generics, attributes, delegates, object and collection initializers, automatic properties, and reflection. These and much more are available in our Design Pattern Framework 4.0TM. See ourSingleton page for a .NET 4.0 Optimized code sample.