Tutorial by Examples: g

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: ...

class Program { static void Main(string[] args) { // Run 2 Tasks. var task1 = Task.Run(() => PerformAction(1))); var task2 = Task.Run(() => PerformAction(2))); // Wait (i.e. block this thread) until both Tasks are complete. Task.WaitA...

An iterator method is not executed until the return value is enumerated. It's therefore advantageous to assert preconditions outside of the iterator. public static IEnumerable<int> Count(int start, int count) { // The exception will throw when the method is called, not when the result i...

For null values: Nullable<int> i = null; Or: int? i = null; Or: var i = (int?)null; For non-null values: Nullable<int> i = 0; Or: int? i = 0;

Given following nullable int int? i = 10; In case default value is needed, you can assign one using null coalescing operator, GetValueOrDefault method or check if nullable int HasValue before assignment. int j = i ?? 0; int j = i.GetValueOrDefault(0); int j = i.HasValue ? i.Value : 0; The ...

Declaring an Event You can declare an event on any class or struct using the following syntax: public class MyClass { // Declares the event for MyClass public event EventHandler MyEvent; // Raises the MyEvent event public void RaiseEvent() { OnMyEvent(); }...

The left-hand operand must be nullable, while the right-hand operand may or may not be. The result will be typed accordingly. Non-nullable int? a = null; int b = 3; var output = a ?? b; var type = output.GetType(); Console.WriteLine($"Output Type :{type}"); Console.WriteLine($&q...

// Connect to a target server using your ConnectionMultiplexer instance IServer server = conn.GetServer("localhost", 6379); // Write out each key in the server foreach(var key in server.Keys()) { Console.WriteLine(key); }

// Connect to a target server using your ConnectionMultiplexer instance IServer server = conn.GetServer("localhost", 6379); var seq = server.Keys(); IScanningCursor scanningCursor = (IScanningCursor)seq; // Use the cursor in some way...

It is possible to use multiple nested using statements without added multiple levels of nested braces. For example: using (var input = File.OpenRead("input.txt")) { using (var output = File.OpenWrite("output.txt")) { input.CopyTo(output); } // output is ...

public class SingletonClass { public static SingletonClass Instance { get; } = new SingletonClass(); private SingletonClass() { // Put custom constructor code here } } Because the constructor is private, no new instances of SingletonClass can be made by consum...

Select allows you to apply a transformation to every element in any data structure implementing IEnumerable. Getting the first character of each string in the following list: List<String> trees = new List<String>{ "Oak", "Birch", "Beech", "Elm", ...

Many LINQ functions both operate on an IEnumerable<TSource> and also return an IEnumerable<TResult>. The type parameters TSource and TResult may or may not refer to the same type, depending on the method in question and any functions passed to it. A few examples of this are public stat...

var name = "World"; var str = $"Hello, {name}!"; //str now contains: "Hello, World!"; Behind the scenes Internally this $"Hello, {name}!" Will be compiled to something like this: string.Format("Hello, {0}!", name);

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

SpeechRecognitionEngine recognitionEngine = new SpeechRecognitionEngine(); GrammarBuilder builder = new GrammarBuilder(); builder.Append(new Choices("I am", "You are", "He is", "She is", "We are", "They are")); builder.Append(new Choices...

Install the NuGet package System.Reactive, then add this using statement to access the Rx extension methods: using System.Reactive.Linq;

emails.Where(email => email.From == "John")

emails.Select(email => email.Body)

Subscription returns an IDisposable: IDisposable subscription = emails.Subscribe(email => Console.WriteLine("Email from {0} to {1}", email.From, email.To)); When you are ready to unsubscribe, simply dispose the subscription: subscription.Dispose();