Why use “new DelegateType(Delegate)”?

Question

Ok, suppose you define a delegate in some class.

public delegate void StringDelegate (string s);

and another class implements a method :

Answer 1

Both are the same, but the latter syntax was added in C#2 to simplify delegate usage.

Both methods compile to the same byte code.

Answer 2

There is absolutely no difference between the two statements. writer = DelegateImplementer.StringWriter; still creates a delegate object; the compiler will generate the new ClassDelegate.StringDelegate () for you. It's just a cleaner syntax that was added in C# 2.0.

As @Ben Voigt mentioned in his answer is only required in C# 2.0 where the compiler can't deduce the type of the delegate, when using Control.Invoke() for example.

Answer 3

The two are equivalent. The latter is syntax new with C# 2.0.

Answer 4

It's syntactic sugar. Ultimately both sets of code do the same thing.

I'd also note that .Net has a bunch of generic delegates built in that can save you alot of coding. In this case I'd do:

Action<string> writer;
writer = DelegateImplementer.StringWriter;
writer ("Hello");

This way you don't even need to create your own delegate.

Answer 5

Sometimes the correct type can't be deduced (like when you're calling a generic), in such a case you need to let the compiler know what kind of delegate you want.

Most of the time, though, naming the method group is easier and clearer.