The State Pattern

 

How many developers does it take to change a lightbulb? With the State pattern, not very many.

Topics include:

• The State Pattern
• Design Patterns
• WPF

Source code available at: https://github.com/JasperKent/The-State-Pattern

IAsyncEnumerable and Yield Return

Getting data from a Web Service? Why wait until it's all arrived before you start processing?

Topics include:

• C#8
• .Net Core
• IAsyncEnumerable<T>
• yield return
• async
• await

Related videos:

• Synchronous Yield Return
  

Source code available at: https://github.com/JasperKent/IAsyncEnumerable-Yield-Return

Synchronous Yield Return

 

Ever wanted to leave a function, and then come back in where you left off? In C# yield return does the trick.

Topics include:

• yield return
• IEnumerable<T>
• Collections
• Fibonacci sequence

Related videos:

• Implementing IEnumerable
  
• IAsyncEnumerable and Yield Return
  

Source code available at: https://github.com/JasperKent/Synchronous-Yield-Return

Collections vs In-Memory Database

 

Entity Framework Core in-memory databases are great for unit testing, but would we ever use them in production code?

Topics include:

• .NET Core
• Entity Framework Core
• In-Memory Database
• Unit Testing
• TDD
• Mocking

Source code available at: https://github.com/JasperKent/In-Memory-Benchmark

C# Extension Methods and the Interface Segregation Principle

 

How do you add a method to and interface without altering the interface? In C#, the answer is extension methods.

Topics include:

• C#
• Extension methods
• SOLID code
• The Interface Segregation Principle
• Turtle graphics
• Kebab casing

Related Videos:

• SOLID: The Interface Segregation Principle
  

Source code available at: https://github.com/JasperKent/Extension-Methods-and-the-ISP

C# Contravariance

Got your head around covariance? Here's contravariance - welcome to opposite land!

Topics include:

• Contravariance
• C#
• Liskov Substitution Principle
• Interfaces
• Delegates
• Sorting

Related videos:

• SOLID: The Liskov Substitution Principle
• C# Covariance
  

Source code available at: https://github.com/JasperKent/Contravariance

C# Covariance

Is a bag of apples a kind of bag of fruit? It all comes down to covariance.

Topics include:

• Covariance
• C#
• Liskov Substitution Principle
• IEnumerable<T>
• List<T>
• Inheritance
• Collections

Related videos:

• SOLID: The Liskov Substitution Principle
  
• C# Contravariance
  

Source code available at: https://github.com/JasperKent/Covariant-Assignment