C# Advanced - Delegates

Video is in Swedish

Title: C#: Advanced - Delegates Explained in Detail

Introduction: In this article, we will delve into the world of advanced C# programming and explore one of its most powerful features: delegates. A delegate is a type of object that represents a method with a specific signature. It allows us to pass methods as arguments to other methods or store them in data structures like arrays or lists.

What are Delegates? A delegate is essentially a pointer to a method, which means it holds the reference to a particular method within its class. This allows for dynamic method invocation and provides flexibility when working with different types of methods. Delegates can be used to represent any type of method, including instance methods, static methods, or even extension methods.

Creating Delegates: To create a delegate in C#, we use the delegate keyword followed by the return type and parameter list of the method we want to represent. For example:

public delegate int MyDelegate(int x, int y);

In this case, MyDelegate is a delegate that represents methods with an integer return type and two integer parameters.

Using Delegates: Once we have created a delegate, we can use it in various ways. One common scenario is to pass the delegate as an argument to another method:

public void ProcessData(MyDelegate myDelegate)
{
    int result = myDelegate(5, 10);
    Console.WriteLine(result);
}

// Example usage:
MyDelegate myDelegate = new MyDelegate(MyMethod);
ProcessData(myDelegate);

int MyMethod(int x, int y)
{
    return x + y;
}

In this example, ProcessData takes a delegate as an argument and uses it to invoke the MyMethod. The result of the method call is then printed to the console.

Another way to use delegates is to store them in data structures like arrays or lists:

public void ProcessData(MyDelegate[] myDelegates)
{
    foreach (var myDelegate in myDelegates)
    {
        int result = myDelegate(5, 10);
        Console.WriteLine(result);
    }
}

// Example usage:
MyDelegate[] myDelegates = new MyDelegate[2];
myDelegates[0] = new MyDelegate(MyMethod1);
myDelegates[1] = new MyDelegate(MyMethod2);

ProcessData(myDelegates);

int MyMethod1(int x, int y)
{
    return x - y;
}

int MyMethod2(int x, int y)
{
    return x * y;
}

In this example, ProcessData takes an array of delegates and iterates through it to invoke each method.

Conclusion: Delegates are a powerful feature in C# that allow us to pass methods as arguments or store them in data structures. They provide flexibility when working with different types of methods and can be used to create more dynamic and reusable code. By understanding how to create, use, and manipulate delegates, we can take our C# programming skills to the next level.

Video