Tutorial by Examples: io

var task1 = Task.Run(() => { Console.WriteLine("Task 1 code starting..."); throw new Exception("Oh no, exception from task 1!!"); }); var task2 = Task.Run(() => { Console.WriteLine("Task 2 code starting..."); throw new Exception("Oh ...

var task1 = Task.Run(() => { Console.WriteLine("Task 1 code starting..."); throw new Exception("Oh no, exception from task 1!!"); }); var task2 = Task.Run(() => { Console.WriteLine("Task 2 code starting..."); throw new Exception("Oh ...

var cancellationTokenSource = new CancellationTokenSource(); var cancellationToken = cancellationTokenSource.Token; var task = new Task((state) => { int i = 1; var myCancellationToken = (CancellationToken)state; while(true) { Console.Write...

Structs inherit from System.ValueType, are value types, and live on the stack. When value types are passed as a parameter, they are passed by value. Struct MyStruct { public int x; public int y; } Passed by value means that the value of the parameter is copied for the method, and any...

Classes inherit from System.Object, are reference types, and live on the heap. When reference types are passed as a parameter, they are passed by reference. public Class MyClass { public int a; public int b; } Passed by reference means that a reference to the parameter is passed to t...

An enum is a special type of class. The enum keyword tells the compiler that this class inherits from the abstract System.Enum class. Enums are used for distinct lists of items. public enum MyEnum { Monday = 1, Tuesday, Wednesday, //... } You can think of an enum as a conve...

You can extend the functionality of existing yield methods by passing in one or more values or elements that could define a terminating condition within the function by calling a yield break to stop the inner loop from executing. public static IEnumerable<int> CountUntilAny(int start, HashSet...

Just like other methods, extension methods can use generics. For example: static class Extensions { public static bool HasMoreThanThreeElements<T>(this IEnumerable<T> enumerable) { return enumerable.Take(4).Count() > 3; } } and calling it would be like: ...

Typically lambdas are used for defining simple functions (generally in the context of a linq expression): var incremented = myEnumerable.Select(x => x + 1); Here the return is implicit. However, it is also possible to pass actions as lambdas: myObservable.Do(x => Console.WriteLine(x)); ...

Use parentheses around the expression to the left of the => operator to indicate multiple parameters. delegate int ModifyInt(int input1, int input2); ModifyInt multiplyTwoInts = (x,y) => x * y; Similarly, an empty set of parentheses indicates that the function does not accept parameters. ...

Explicit interface implementation is necessary when you implement multiple interfaces who define a common method, but different implementations are required depending on which interface is being used to call the method (note that you don't need explicit implementations if multiple interfaces share t...

using System.Speech.Recognition; // ... SpeechRecognitionEngine recognitionEngine = new SpeechRecognitionEngine(); recognitionEngine.LoadGrammar(new DictationGrammar()); recognitionEngine.SpeechRecognized += delegate(object sender, SpeechRecognizedEventArgs e) { Console.WriteLine(&quot...

emails.Subscribe(email => Console.WriteLine("Email from {0} to {1}", email.From, email.To), cancellationToken);

Event declaration: public event EventHandler<EventArgsT> EventName; Event handler declaration: public void HandlerName(object sender, EventArgsT args) { /* Handler logic */ } Subscribing to the event: Dynamically: EventName += HandlerName; Through the Designer: Click the Events...

Event declaration: public event EventHandler<EventArgsType> EventName; Event handler declaration using lambda operator => and subscribing to the event: EventName += (obj, eventArgs) => { /* Handler logic */ }; Event handler declaration using delegate anonymous method syntax: Eve...

Events can be of any delegate type, not just EventHandler and EventHandler<T>. For example: //Declaring an event public event Action<Param1Type, Param2Type, ...> EventName; This is used similarly to standard EventHandler events: //Adding a named event handler public void HandlerNa...

Given an IObservable<Offer> of offers from merchants to buy or sell some type of item at a fixed price, we can match pairs of buyers and sellers as follows: var sellers = offers.Where(offer => offer.IsSell).Select(offer => offer.Merchant); var buyers = offers.Where(offer => offer.Is...

using System.Linq.Expressions; // Manually build the expression tree for // the lambda expression num => num < 5. ParameterExpression numParam = Expression.Parameter(typeof(int), "num"); ConstantExpression five = Expression.Constant(5, typeof(int)); BinaryExpression numLessTh...

// Define an expression tree, taking an integer, returning a bool. Expression<Func<int, bool>> expr = num => num < 5; // Call the Compile method on the expression tree to return a delegate that can be called. Func<int, bool> result = expr.Compile(); // Invoke the dele...

using System.Linq.Expressions; // Create an expression tree. Expression<Func<int, bool>> exprTree = num => num < 5; // Decompose the expression tree. ParameterExpression param = (ParameterExpression)exprTree.Parameters[0]; BinaryExpression operation = (BinaryExpression)exp...