C#: meaning of statement... Action wrappedAction = () =>

Question

Saw the code here. Can any one tell me what it means?

    Action wrappedAction = () => 
    { 
        threadToKill = Thread.CurrentThread; 
        action(); 
    }; 

Can we write such code with .net v2.0...?

Answer 1

It means that wrapAction is a delegate, that takes in no parameter and that executes the following code block

  threadToKill = Thread.CurrentThread; 
  action();

It's equivalent to

public delegate void wrapActionDel(); 

public void wrapAction()
{
      threadToKill = Thread.CurrentThread; 
      action();
}

public void CallwrapAction()
{
   wrapActionDel del = wrapAction;
   del ();
}

You can see that this is verbose, but Action is not.

And, this is only available in .Net 3.5. Don't worry, your .net 2.0 code will work seamlessly with .net 3.5, so you can just upgrade.

Answer 2

That is a lambda expression, and is only available in C# 3.0+. The C# 2.0 version of that code looks like this:

Action wrappedAction = delegate() 
{ 
    threadToKill = Thread.CurrentThread; 
    action(); 
};

Assuming you have declared the Action delegate previously.