Question

For example:

delegate void SomeDelegate();

SomeDelegate a = new SomeDelegate( () => Console.WriteLine("A") );
SomeDelegate b = new SomeDelegate( () => Console.WriteLine("B") );

SomeDelegate c = a + b;

In the last line, what does a + b translate to? I’m just curious how I would add them without using the + operator.

Answer 1

http://msdn.microsoft.com/en-us/library/ms173172(v=VS.80).aspx – Search for addition:

A delegate can call more than one method when invoked. This is
referred to as multicasting. To add an extra method to the delegate’s
list of methods—the invocation list—simply requires adding two
delegates using the addition or addition assignment operators (‘+’ or
‘+=’). For example:

MethodClass obj = new MethodClass(); 
Del d1 = obj.Method1; 
Del d2 = obj.Method2; 
Del d3 = DelegateMethod;

//Both types of assignment are valid. 
Del allMethodsDelegate = d1 + d2; 
allMethodsDelegate += d3;

At this point allMethodsDelegate contains three methods in its
invocation list—Method1, Method2, and DelegateMethod. The original
three delegates, d1, d2, and d3, remain unchanged. When
allMethodsDelegate is invoked, all three methods are called in order.
If the delegate uses reference parameters, the reference is passed
sequentially to each of the three methods in turn, and any changes by
one method are visible to the next method. When any of the methods
throws an exception that is not caught within the method, that
exception is passed to the caller of the delegate and no subsequent
methods in the invocation list are called.

Update

Both delegates derive from System.Delegate You can use the combine() methods to add two delegates together.