Slides from my April 2014 presentation to the Vermont .NET user group.

1. Back to Basics:
Delegates
Rob Hale
April 21, 2014

2. Goals
● Delegation pattern review
● Delegates in C#

3. Delegation
Design Pattern

4. Delegation design pattern - simple
Delegator Delegatee

5. Delegation design pattern
- slightly more complicated
Delegator IDelegatee
Concrete
Delegatee1
Concrete
Delegatee2

6. Coding time...

7. Delegates in C#

8. What are Delegates?
● Delegates are a reference type that defines
a method signature
○ Like C++ function pointers but are type safe
○ Unlike method overloading, the return type is part of
the signature
● They allow methods to be passed as
parameters
● They can be used to define callback
methods
● They can be chained together
○ For example, multiple methods can be called on a

9. Coding Time...

10. Resources
Code from this presentation
● https://github.
com/robhalevt/20140421_VTdotNET_DelegationAndDelegates
Other reading
● http://msdn.microsoft.com/en-us/library/vstudio/ms173171(v=vs.100).aspx
● http://msdn.microsoft.com/en-us/library/orm-9780596516109-03-09.aspx
● http://en.wikipedia.org/wiki/Delegation_pattern
● http://stackoverflow.com/questions/2044301/what-is-delegate