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public class SomeClass { public void DoStuff() { } protected void DoMagic() { } } public static class SomeClassExtensions { public static void DoStuffWrapper(this SomeClass someInstance) { someInstance.DoStuff(); // ok ...

List<int> l2 = l1.FindAll(x => x > 6); Here x => x > 6 is a lambda expression acting as a predicate that makes sure that only elements above 6 are returned.

When you want to catch an exception and do something, but you can't continue execution of the current block of code because of the exception, you may want to rethrow the exception to the next exception handler in the call stack. There are good ways and bad ways to do this. private static void AskTh...

public class Person { //Id property can be read by other classes, but only set by the Person class public int Id {get; private set;} //Name property can be retrieved or assigned public string Name {get; set;} private DateTime dob; //Date of Birth property is st...

public delegate int ModifyInt(int input); ModifyInt multiplyByTwo = x => x * 2; The above Lambda expression syntax is equivalent to the following verbose code: public delegate int ModifyInt(int input); ModifyInt multiplyByTwo = delegate(int x){ return x * 2; };

var letters = "letters".ToCharArray(); char letter = letters[1]; Console.WriteLine("Second Letter is {0}",letter); //in the above example we take the second character from the array //by calling letters[1] //NB: Array Indexing starts at 0; i.e. the first letter would be give...

var letters = null; char? letter = letters?[1]; Console.WriteLine("Second Letter is {0}",letter); //in the above example rather than throwing an error because letters is null //letter is assigned the value null

Deprecated usage The ConfigurationSettings class was the original way to retrieve settings for an assembly in .NET 1.0 and 1.1. It has been superseded by the ConfigurationManager class and the WebConfigurationManager class. If you have two keys with the same name in the appSettings section of the ...

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 dateString = "2015-11-24"; var date = DateTime.ParseExact(dateString, "yyyy-MM-dd", null); Console.WriteLine(date); 11/24/2015 12:00:00 AM Note that passing CultureInfo.CurrentCulture as the third parameter is identical to passing null. Or, you can pass a specific...

using System.Collections.Generic; using System.Collections.ObjectModel; using System.ComponentModel.Composition; namespace Demo { [Export(typeof(IUserProvider))] public sealed class UserProvider : IUserProvider { public ReadOnlyCollection<User> GetAllUsers() ...

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: ...

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...

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

Unlike interfaces, which can be described as contracts for implementation, abstract classes act as contracts for extension. An abstract class cannot be instantiated, it must be extended and the resulting class (or derived class) can then be instantiated. Abstract classes are used to provide generi...

The Except method returns the set of items which are contained in the first collection but are not contained in the second. The default IEqualityComparer is used to compare the items within the two sets. There is an overload which accepts an IEqualityComparer as an argument. Example: int[] first =...

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...