Tutorial by Examples: o

using System; using System.IO; using System.Linq; using System.Net.Http; using System.Threading.Tasks; class HttpGet { private static async Task DownloadAsync(string fromUrl, string toFile) { using (var fileStream = File.OpenWrite(toFile)) { using (va...

goto can be used to jump to a specific line inside the code, specified by a label. goto as a: Label: void InfiniteHello() { sayHello: Console.WriteLine("Hello!"); goto sayHello; } Live Demo on .NET Fiddle Case statement: enum Permissions { Read, Write }; switch ...

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.

string[] strings = new[] {"foo", "bar"}; object[] objects = strings; // implicit conversion from string[] to object[] This conversion is not type-safe. The following code will raise a runtime exception: string[] strings = new[] {"Foo"}; object[] objects = strings;...

public async Task<JobResult> GetDataFromWebAsync() { var nextJob = await _database.GetNextJobAsync(); var response = await _httpClient.GetAsync(nextJob.Uri); var pageContents = await response.Content.ReadAsStringAsync(); return await _database.SaveJobResultAsync(pageContents); } ...

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...

// default value of boolean is false bool b; //default value of nullable boolean is null bool? z; b = true; if(b) { Console.WriteLine("Boolean has true value"); } The bool keyword is an alias of System.Boolean. It is used to declare variables to store the Boolean values, true...

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...

class Program { public static void Main(string[] args) { Person aPerson = new Person("Ann Xena Sample", new DateTime(1984, 10, 22)); //example of accessing properties (Id, Name & DOB) Console.WriteLine("Id is: \t{0}\nName is:\t'{1}'.\nDOB is...

public class Model { public string Name { get; set; } public bool? Selected { get; set; } } Here we have a Class with no constructor with two properties: Name and a nullable boolean property Selected. If we wanted to initialize a List<Model>, there are a few different ways to ex...

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; };

class Program { static void Main(string[] args) { // Create 2 thread objects. We're using delegates because we need to pass // parameters to the threads. var thread1 = new Thread(new ThreadStart(() => PerformAction(1))); var thread2 = new Thread(...

var now = DateTime.UtcNow; //accesses member of a class. In this case the UtcNow property.

var zipcode = myEmployee?.Address?.ZipCode; //returns null if the left operand is null. //the above is the equivalent of: var zipcode = (string)null; if (myEmployee != null && myEmployee.Address != null) zipcode = myEmployee.Address.ZipCode;

var age = GetAge(dateOfBirth); //the above calls the function GetAge passing parameter dateOfBirth.

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

using st = System.Text; //allows you to access classes within this namespace such as StringBuilder //prefixing them with only the defined alias and not the full namespace. i.e: //... var sb = new st.StringBuilder(); //instead of var sb = new System.Text.StringBuilder();

6.0 Allows you to import a specific type and use the type's static members without qualifying them with the type name. This shows an example using static methods: using static System.Console; // ... string GetName() { WriteLine("Enter your name."); return ReadLine(); } ...

Notes: This example must be run in administrative mode. Only one simultaneous client is supported. For simplicity, filenames are assumed to be all ASCII (for the filename part in the Content-Disposition header) and file access errors are not handled. using System; using System.IO; using Syst...