C# Language
- Getting started with C# Language
- Learn Tutorial
- How to Start Learning C# While Still in College
- Awesome Book
- Awesome Community
- Awesome Course
- Awesome Tutorial
- Awesome YouTube
- .NET Compiler Platform (Roslyn)
- Access Modifiers
- Access network shared folder with username and password
- Accessing Databases
- Action Filters
- Aliases of built-in types
- An overview of c# collections
- Anonymous types
- Arrays
- ASP.NET Identity
- AssemblyInfo.cs Examples
- Async/await, Backgroundworker, Task and Thread Examples
- Async-Await
- Asynchronous Socket
- Attributes
- BackgroundWorker
- BigInteger
- Binary Serialization
-
BindingList
- Built-in Types
- C# 3.0 Features
- C# 4.0 Features
- C# 5.0 Features
- C# 6.0 Features
- C# 7.0 Features
- C# Authentication handler
- C# Script
- Caching
- Casting
- Checked and Unchecked
- CLSCompliantAttribute
- Code Contracts
- Code Contracts and Assertions
- Collection Initializers
- Comments and regions
- Common String Operations
- Conditional Statements
- Constructors and Finalizers
- Creating a Console Application using a Plain-Text Editor and the C# Compiler (csc.exe)
- Creating Own MessageBox in Windows Form Application
- Creational Design Patterns
- Cryptography (System.Security.Cryptography)
- Data Annotation
- DateTime Methods
- Delegates
- Dependency Injection
- Diagnostics
- Dynamic type
- Enum
- Equality Operator
- Equals and GetHashCode
- Events
- Exception Handling
- Expression Trees
- Extension Methods
- File and Stream I/O
- FileSystemWatcher
- Func delegates
- Function with multiple return values
- Functional Programming
- Garbage Collector in .Net
- Generating Random Numbers in C#
- Generic Lambda Query Builder
- Generics
- Checking equality of generic values.
- Configuration reader with generic type casting
- Contravariance
- Covariance
- Explicit type parameters
- Generic type casting
- Implicit type inference (methods)
- Invariance
- Reflecting on type parameters
- Type constraints (class and struct)
- Type constraints (classes and interfaces)
- Type constraints (new-keyword)
- Type inference (classes)
- Type Parameters (Classes)
- Type Parameters (Interfaces)
- Type Parameters (Methods)
- Using generic method with an interface as a constraint type.
- Variant delegates
- Variant interfaces
- Variant types as parameters and return values
- Getting Started: Json with C#
- Guid
- Handling FormatException when converting string to other types
- Hash Functions
- How to use C# Structs to create a Union type (Similar to C Unions)
- ICloneable
- IComparable
- IDisposable interface
- IEnumerable
- ILGenerator
- Immutability
- Implementing Decorator Design Pattern
- Implementing Flyweight Design Pattern
- Import Google Contacts
- Including Font Resources
- Indexer
- Inheritance
- Initializing Properties
- INotifyPropertyChanged interface
- Interfaces
- Interoperability
- IQueryable interface
- Iterators
- Keywords
- Lambda expressions
- Lambda Expressions
- LINQ Queries
- Linq to Objects
- LINQ to XML
- Literals
- Lock Statement
- Looping
- Making a variable thread safe
- Methods
- Microsoft.Exchange.WebServices
- Named and Optional Arguments
- Named Arguments
- nameof Operator
- Naming Conventions
- Networking
- Nullable types
- Null-Coalescing Operator
- Null-conditional Operators
- NullReferenceException
- O(n) Algorithm for circular rotation of an array
- Object initializers
- Object Oriented Programming In C#
-
ObservableCollection
- Operators
- Overflow
- Overload Resolution
- Parallel LINQ (PLINQ)
- Partial class and methods
- Performing HTTP requests
- Pointers
- Pointers & Unsafe Code
- Polymorphism
- Preprocessor directives
- Properties
- Reactive Extensions (Rx)
- Read & Understand Stacktraces
- Reading and writing .zip files
- Recursion
- Reflection
- Regex Parsing
- Runtime Compile
- Singleton Implementation
- Static Classes
- Stopwatches
- Stream
- String Concatenate
- String Escape Sequences
- String Interpolation
- String Manipulation
- String.Format
- StringBuilder
- Structs
- Structural Design Patterns
- Synchronization Context in Async-Await
- System.DirectoryServices.Protocols.LdapConnection
- System.Management.Automation
- T4 Code Generation
- Task Parallel Library
- Task Parallel Library (TPL) Dataflow Constructs
- Threading
- Timers
- Tuples
- Type Conversion
- Unsafe Code in .NET
- Using Directive
- Using json.net
- Using SQLite in C#
- Using Statement
- Value type vs Reference type
- Verbatim Strings
- Windows Communication Foundation
- XDocument and the System.Xml.Linq namespace
- XML Documentation Comments
- XmlDocument and the System.Xml namespace
- Yield Keyword
C# Language Generics Invariance
Example
IList<T> is never a subtype of a different IList<T1>. IList is invariant in its type parameter.
class Animal { /* ... */ }
class Dog : Animal { /* ... */ }
IList<Dog> dogs = new List<Dog>();
IList<Animal> animals = dogs; // type error
There is no subtype relationship for lists because you can put values into a list and take values out of a list.
If IList was covariant, you'd be able to add items of the wrong subtype to a given list.
IList<Animal> animals = new List<Dog>(); // supposing this were allowed...
animals.Add(new Giraffe()); // ... then this would also be allowed, which is bad!
If IList was contravariant, you'd be able to extract values of the wrong subtype from a given list.
IList<Dog> dogs = new List<Animal> { new Dog(), new Giraffe() }; // if this were allowed...
Dog dog = dogs[1]; // ... then this would be allowed, which is bad!
Invariant type parameters are declared by omitting both the in and out keywords.
interface IList<T> { /* ... */ }
