Standard delegates in C#

c# list delegates
Tarion picture Tarion · Apr 8, 2009 · Viewed 20.6k times · Source

There are some Delegates predefined in C#

I know these:

EventHandler // Default event callbacks
EventHandler<T> // Default event callbacks with custom parameter (inheriting from EventArgs)
Action // Function without return value and without parameter
Action<T1, T2, T3, T4> // Function without return value and 1-4 parameters
Func<T1, T2, T3, T4, TResult> // Methos with 0-4 parameters and one result type
Predicate<T> // equivalent to Func<T, bool>

There are many more for special cases and generated form parts of the framework, but these are often good to use in self written code.

If you know some more useful add them. Otherwise this is answered.

Answer

Jon Skeet picture Jon Skeet · Apr 8, 2009

They're not predefined in C#. They're defined by the framework.

The Action and Func delegate families are wider than you've shown - they go up to

Action<T1, T2, T3, T4>

and

Func<T1, T2, T3, T4, TResult>

Another common-ish one in .NET 2.0 for list manipulation (before LINQ) is Predicate<T>.

For working with threads:

ThreadStart
ParameterizedThreadStart
WaitCallback
TimerCallback
AsyncCallback

Related questions

C# - using List<T>.Find() with custom objects

I'm trying to use a List<T> with a custom class of mine, and being able to use methods like Contains(), Find(), etc., on the list. I thought I'd just have to overload the operator == but apparently, one …

Read More
How do I form a good predicate delegate to Find() something in my List<T>?

After looking on MSDN, it's still unclear to me how I should form a proper predicate to use the Find() method in List using a member variable of T (where T is a class) For example: public class Car { public …

Read More
How to Sort a List<T> by a property in the object

I have a class called Order which has properties such as OrderId, OrderDate, Quantity, and Total. I have a list of this Order class: List<Order> objListOrder = new List<Order>(); GetOrderList(objListOrder); // fill list of orders …

Read More