C# => operator?

Question

I have a question about the => operator in C#.

I am looking at the Expression Blend 4 samples. There is one line in the Contact sample which includes:

//In C:\Program Files (x86)\Microsoft Expression\Blend 4\Samples\en\Contacts\ //Contacts\ViewModels\ContactsViewModel.cs:   contactDetailWindow.Closed += (o, e) => {                                  finishedCallback(contactDetailWindow.DialogResult);     // Or, C:\Program Files (x86)\Microsoft Expression\Blend 4\Samples\en\    // Contacts\Contacts\ViewModels\ContactsViewModel.cs    this.EditContact(newContact, dialogResult =>    {         if (dialogResult.HasValue && dialogResult.Value)         {         this.Contacts.Add(newContact);         }    }); }; 

What is the => operator actually doing? Is it overriding something?

Answer 1

It's called the lambda operator.

 b.Click += (s, e) => Log("Sender :" + s + "EventArgs " + e); 

is identical to

b.Click += b_Click;  void b_Click(object sender, EventArgs e) {     Log("Sender :" + sender + "EventArgs " + e); } 

or

b.Click += delegate(object sender, EventArgs e)             {                 Log("Sender :" + sender + "EventArgs " + e);              };