SendMessage with receiver in c#

Scripting C# & .NET
1

How can I program SendMessage() with a receiver in C#?
In JS I can use in one object SendMessage like(“nameOfReceiverfunction”, true);
and in the receiving object:
function nameOfReceiverfunction (on: bool)
{
//do what you need with this message
}
How do I achieve the same in C#? (I know I can use GetComponent(), but I would like to really use SendMessage. Do I need delegates? .NET event handling?

Thanks for your answer.

2

It looks exactly the same as in js, difference is that the function declaration looks slightly different as you can see below.
But the rest is 100% equal and a single sendmessage can trigger a unityscript, C and boo function in the same go on the same GO if it wants to

void nameOfReceiverfunction (bool on) 
{ 
//do what you need with this message 
}