C# Conversion of lambda expression

Question

What is the way to convert the following into lambda expression?

ThreadPool.QueueUserWorkItem(delegate
     {
        Console.WriteLine("Current Thread Id is {0}:",
         Thread.CurrentThread.ManagedThreadId);
        Console.WriteLine("I will be used as Callback");
      }
    );

Answer 1

You could definitely write this as a lambda expression:

// The underscore is simply a placeholder for the "state"
// parameter that the WaitCallback delegate expects - you could
// use any character but you must specify one as lamba expressions cannot
// omit parameters like anonymous functions can.
ThreadPool.QueueUserWorkItem((_) =>
    {
     Console.WriteLine("Current Thread Id is {0}:",
     Thread.CurrentThread.ManagedThreadId);
     Console.WriteLine("I will be used as Callback");
    });

But remember that a lambda expression has no meaning outside of your source code. The C# compiler will convert your lambda expression right back to the code you have now.

A lambda expression is simply syntactic sugar that you can use to express an anonymous function - the compiler will convert this to either an anonymous function or an expression tree.