C# 0 The Complete Reference

EventArgs

 called 

KeyEventArgs

, which is 

used to pass a keystroke to an event handler. Next, a delegate called 

KeyHandler

 defines 

the event handler for keystroke events. The class 

KeyEvent

 encapsulates the keypress event. 

It defines the event 

KeyPress

.

In

Main( )

, a 

KeyEvent

 object called 

kevt

 is created. Next, an event handler based on 

a lambda expression is added to 

kvet.KeyPress

 that displays each key as it is entered, as 

shown here:

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PART I

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PART IPART I

kevt.KeyPress += (source, arg) =>

  Console.WriteLine(" Received keystroke: " + arg.ch);

Next, another lambda expression–based handler is added to 

kvet.KeyPress

 by the 

following code. It counts the number of keypresses.

kevt.KeyPress += (source, arg) =>

  count++; // count is an outer variable

Notice that 

count

 is a local variable declared in 

Main( )

 that is initialized to zero.

Next, a loop is started that calls