Tutorial by Examples: co



class ToyProfiler : IProfiler { public ConcurrentDictionary<Thread, object> Contexts = new ConcurrentDictionary<Thread, object>(); public object GetContext() { object ctx; if(!Contexts.TryGetValue(Thread.CurrentThread, out ctx)) ctx = null; ...
ConnectionMultiplexer conn = /* initialization */; var profiler = new ToyProfiler(); conn.RegisterProfiler(profiler); var threads = new List<Thread>(); var perThreadTimings = new ConcurrentDictionary<Thread, List<IProfiledCommand>>(); for (var i = 0; i < 16; i++) {...
IDBConnection db = /* ... */ var id = /* ... */ db.Execute(@"update dbo.Dogs set Name = 'Beowoof' where Id = @id", new { id });
public class IHtmlStringTypeHandler : SqlMapper.TypeHandler<IHtmlString> { public override void SetValue( IDbDataParameter parameter, IHtmlString value) { parameter.DbType = DbType.String; parameter.Value = value?.ToHtmlString(); } pu...
Open Visual Studio In the toolbar, go to File → New Project Select the Console Application project type Open the file Program.cs in the Solution Explorer Add the following code to Main(): public class Program { public static void Main() { // Prints a message to the conso...
Initialize a collection type with values: var stringList = new List<string> { "foo", "bar", }; Collection initializers are syntactic sugar for Add() calls. Above code is equivalent to: var temp = new List<string>(); temp.Add("foo"); temp.A...
When a type is defined without a constructor: public class Animal { } then the compiler generates a default constructor equivalent to the following: public class Animal { public Animal() {} } The definition of any constructor for the type will suppress the default constructor genera...
public class Animal { public string Name { get; set; } public Animal() : this("Dog") { } public Animal(string name) { Name = name; } } var dog = new Animal(); // dog.Name will be set to "Dog" by default. var cat = new Ani...
A static constructor is called the first time any member of a type is initialized, a static class member is called or a static method. The static constructor is thread safe. A static constructor is commonly used to: Initialize static state, that is state which is shared across different instan...
A constructor of a base class is called before a constructor of a derived class is executed. For example, if Mammal extends Animal, then the code contained in the constructor of Animal is called first when creating an instance of a Mammal. If a derived class doesn't explicitly specify which constru...
var numbers = new[] {1,2,3,4,5}; Console.WriteLine(numbers.Contains(3)); //True Console.WriteLine(numbers.Contains(34)); //False
var numbers1to5 = new[] {1, 2, 3, 4, 5}; var numbers4to8 = new[] {4, 5, 6, 7, 8}; var numbers1to8 = numbers1to5.Concat(numbers4to8); Console.WriteLine(string.Join(",", numbers1to8)); //1,2,3,4,5,4,5,6,7,8 Note that duplicates are kept in the result. If this is undesirable, use...
IEnumerable<int> numbers = new[] {1,2,3,4,5,6,7,8,9,10}; var numbersCount = numbers.Count(); Console.WriteLine(numbersCount); //10 var evenNumbersCount = numbers.Count(n => (n & 1) == 0); Console.WriteLine(evenNumbersCount); //5
const is used to represent values that will never change throughout the lifetime of the program. Its value is constant from compile-time, as opposed to the readonly keyword, whose value is constant from run-time. For example, since the speed of light will never change, we can store it in a constan...
Immediately pass control to the next iteration of the enclosing loop construct (for, foreach, do, while): for (var i = 0; i < 10; i++) { if (i < 5) { continue; } Console.WriteLine(i); } Output: 5 6 7 8 9 Live Demo on .NET Fiddle var stuff = new [] ...
To make a class support collection initializers, it must implement IEnumerable interface and have at least one Add method. Since C# 6, any collection implementing IEnumerable can be extended with custom Add methods using extension methods. class Program { static void Main() { va...
string sqrt = "\u221A"; // √ string emoji = "\U0001F601"; // 😁 string text = "\u0022Hello World\u0022"; // "Hello World" string variableWidth = "\x22Hello World\x22"; // "Hello World"
The ?. operator is syntactic sugar to avoid verbose null checks. It's also known as the Safe navigation operator. Class used in the following example: public class Person { public int Age { get; set; } public string Name { get; set; } public Person Spouse { get; set; } } If a...
Similarly to the ?. operator, the null-conditional index operator checks for null values when indexing into a collection that may be null. string item = collection?[index]; is syntactic sugar for string item = null; if(collection != null) { item = collection[index]; }
Click the menus Tools -> NuGet Package Manager -> Package Manager Console to show the console in your IDE. Official documentation here. Here you can issue, amongst others, install-package commands which installs the entered package into the currently selected "Default project": Ins...

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