Alright, let’s cut through the crap and get to it:
⚡️ What is a delegate in C#?
A delegate is basically a type-safe function pointer. It lets you store references to methods, so you can pass them around like variables.It's like saying:
"Hey C#, here's a method. I might call it later. I might pass it to someone else to call. But trust me, it's the right kind of method."
🔧 Syntax example:
csharp
public delegate int MathOp(int x, int y); int Add(int a, int b) => a + b; MathOp op = Add; int result = op(3, 4); // result = 7
Yeah, it looks old-school. That’s because it is — delegates were around before lambdas were cool.
🧠 When to use them:
You use delegates when you want to pass behavior around as data, especially:
- Call back later – Like saying, “Do this when you're done.”
csharp
void DoSomethingAsync(Action callback) { // ... do stuff ... callback(); }
- Plugins / strategies – Injecting different methods to alter behavior.
csharp
Func formatter = s => s.ToUpper(); Console.WriteLine(formatter("hello")); // Outputs: HELLO
- Events – The real killer use case in C#. Delegates are the backbone of the event system.
csharp
public delegate void SomethingHappenedHandler(string message); public event SomethingHappenedHandler OnSomethingHappened;
🧪 The Modern Reality:
In real code, you almost never write delegate manually anymore.Instead, you use:
Action– when there's no return valueFunc– when you want to return something
Examples:
csharp
Action sayHi = () => Console.WriteLine("Hi!"); Func add = (a, b) => a + b;
🪤 When not to bother:
- If you’re writing spaghetti code just to “use delegates” — stop.
- If you're trying to be clever in business logic and it's not saving you complexity — don't.
- If you're writing handlers but never wiring them up — it's just dead code.
🗣️ So, should you use them?
Yes, when:
- You want flexible behavior passed around.
- You're building events, callbacks, or plugins.
- You need abstractions without interfaces. No, when:
- You’re trying to shoehorn them into places where a regular method would do.
- You don’t fully understand what the delegate is pointing to or when it’s invoked.