Deck 13: Handling Events

Question 1

What class has a static field named Empty that represents an event that contains no event data?

A) delegate
B) EventArgs
C) EventHandler
D) MouseArgs

Answer 1

B

Question 2

Events must be declared as private.

Answer 2

False

Question 3

The C# language requires that every event must use a delegate type with three parameters.

Answer 3

False

Question 4

In a button event-handler parameter list, the second argument is an object of what type?

A) MouseEventArgs
B) KeyEventArgs
C) EventArgs
D) KeyPressEventArgs

Question 5

The code generated in Design mode in the IDE is not meant to be altered by typing.You should modify Control properties through the Properties window in the IDE.

Question 6

A C# delegate is similar to what variable type in C++ that holds a method's memory address?

A) object pointer
B) integer pointer
C) function pointer
D) reference pointer

Question 7

What event occurs when the mouse cursor leaves the Control's boundaries?

A) MouseClick
B) MouseEnter
C) MouseHover
D) MouseLeave

Question 8

What file can be opened to examine all the code generated by the Windows Form Designer for an application that creates a Form?

A) Designer.cs
B) EventHandlers.cs
C) Project.cs
D) Form.cs

Question 9

What event occurs when the user clicks the mouse within the Control's boundaries?

A) MouseClick
B) MouseEnter
C) MouseHover
D) MouseLeave

Question 10

What keyword can be used to declare a delegate?

A) handler
B) function
C) pointer
D) delegate

Question 11

What provides a way for the clients of a class to dictate methods that should execute when an event occurs?

A) a handler
B) an event
C) a delegate
D) a trigger

Question 12

When you double-click a Button on a Form in the IDE, you automatically generate the shell of what method?

A) Click()
B) Double_Click()
C) Enter()
D) Focus()

Question 13

What term can be used to describe an event-handler method?

A) event source
B) event sender
C) sender object
D) event receiver

Question 14

What is used to declare your own event in C#?

A) handlers
B) trigger objects
C) delegates
D) raisers

Question 15

When an event occurs, any delegate that a client has given or passed to the event is invoked.

Question 16

Any delegate can encapsulate any method that has the same return type and parameter list as the delegate.

Question 17

What is another term for the performing of an action, such as the click of a button by a user?

A) raising an event
B) closing a loop
C) deleting an instance
D) chaining an action

Question 18

In C#, when something interesting happens to an object, what is said to have occurred?

A) an error
B) an event
C) a memory dump
D) a method callback

Question 19

For events that do not use additional information, the .NET Framework has already defined an appropriate delegate type with what name?

A) EventArgs
B) EventTrigger
C) EventPush
D) EventHandler

Question 20

Mouse events can be handled for any control through an object of what class?

A) MouseEvent
B) MouseEventArgs
C) MousePressEventArgs
D) MousePressArgs

Question 21

When users encounter multiple GUI Controls on a Form, and a user presses the Enter key, what usually happens?

A) The Form will check the default key action for the enter key in the Designer.cs file.
B) The Control that has focus will raise an event.
C) The Control that is closest to the mouse pointer will be activated.
D) Nothing will happen unless the enter key has a KeyPressHandler event defined.

Question 22

What are the properties of the MouseEventArgs class?

Question 23

What is an important difference between KeyEventArgs properties and KeyPressEventArgs properties?

Question 24

What Boolean property of a Control identifies whether the Control will serve as a stopping place in a sequence of Tab key presses?

A) TabIndex
B) TabCount
C) TabStop
D) TabFlag

Question 25

An event that occurs as a result of interaction with the keyboard is known as what type of event?

A) key events
B) external events
C) input events
D) console events

Question 26

The connection of an event to its resulting actions is known by what term?

A) event wiring
B) event triggering
C) event watching
D) event connecting

Question 27

Describe the methods that could be encapsulated by a delegate that has been defined as: delegate void GreetingDelegate(string s);

Question 28

What are the two actions that can be taken on an event field?

Question 29

What property stores the key code along with any modifier key for a key event?

A) KeyCode
B) KeyValue
C) KeyData
D) KeyStatus

Question 30

What are common keyboard events? What is the delegate used to create a keyboard event handler, and what is the type of the second parameter to the event handler?

Question 31

Depending on the event, the delegate used to create the keyboard event handler is either KeyEventHandler or what other event handler?

A) PressEventHandler
B) EventHandler
C) KeyPressHandler
D) KeyPressEventHandler

Question 32

Assume you declare three delegates named delegate1, delegate2, and delegate3.You then assign a reference to method M1() to delegate1, and a reference to method M2() to delegate2.How do you make delegate3 into a composed delegate that executes both M1() and M2()? What are the rules concerning return type and parameter list for composed delegates?

Question 33

What event occurs when a mouse button is released while the mouse is within the Control's boundaries?

A) MouseClick
B) MouseHover
C) MouseUp
D) MouseMove

Question 34

When a Form contains multiple Controls, you can create a separate event handler for each Control.However, you can also associate the same event handler with multiple Controls.Describe how to associate an existing event handler with a second Control using the IDE.

Question 35

What expression describes the act of calling an event method?

A) cascading the event
B) revoking the event
C) invoking the event
D) composing the event

Question 36

Given a GUI Control, what objects and delegates are provided to handle mouse events such as clicking, pointing, and dragging?

Question 37

What is the relationship between an event sender and event receiver?

Question 38

What happens when the TabIndex values of two or more Controls is set to 0?

A) An Exception is thrown, and the program ends.
B) No errors are generated, but only one Control will receive focus.
C) After setting one Control to 0, the other Control will be forced to a 1 or other unique number.
D) Both Controls will receive focus at the same time.

Question 39

When you define your own event-handler delegate, what arguments are required? Provide an example of a delegate declaration.

Question 40

For static methods, what does a delegate object encapsulate?

A) The class utilized by the methods.
B) The arguments passed to the methods.
C) The method to be called.
D) Custom events defined within the methods.

Question 41

When you click a component on a Form in Design View, you move to the default method code.