In programming, a delegate is a type that represents a reference to a method. It’s similar to a function pointer in C, but it’s type-safe and easier to use.
Delegates are used in many situations where you want to pass a method as an argument to another method. For example, you might use a delegate to specify a method to be called back when an event occurs, or to specify a method to be used as a comparer when sorting a list.
Here’s an example of how you might use a delegate in C#:
using System;
delegate int MyDelegate(int x, int y);
class Program
{
static int Add(int x, int y) { return x + y; }
static int Multiply(int x, int y) { return x * y; }
static void Main(string[] args)
{
MyDelegate d1 = Add;
MyDelegate d2 = Multiply;
Console.WriteLine(d1(3, 4)); // Outputs 7
Console.WriteLine(d2(3, 4)); // Outputs 12
}
}
In this example, the MyDelegate type represents a reference to a method that takes two int arguments and returns an int. The Add and Multiply methods have the same signature, so they can be assigned to variables of type MyDelegate.