I am writing delegates as like this.
delegate void MyMethod(string arg1, string arg2);
MyMethod mm;
I don't know why it needs two lines to declare a single delegate. If my class has 20 delegates, I need to write 40 line of code. Can anybody tell me a way to write this in one line of code ? Thanks in Advance.

You're declaring two very different things here:
MyMethodIt's important to understand the difference, because then you can work out when you really want to declare a new delegate type and when you just want to declare a field of an existing delegate type. If your class has 20 delegate fields, you almost certainly don't want to declare a new type for each of them. If they've got the same signature, you could use a single type... or better, just use one of the framework types such as Action<...> or Func<...>.
Action<string, string> mm;
(There are Action delegates for void return types, and Func delegates for non-void return types, with different numbers of parameters, all expressed generically. Look at MSDN for more details.)
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