Question 1

A MethodInvoker (namespace System.Windows.Forms)is a ________.

Accepted Answer

A)  a single-argument constructor 
B)  Delegate that invokes a method with no arguments and a void return type 
C)  an interface that must be implemented 
D)  an indirect proxy caller

Question 2

When you await a Task,if that Task has already completed,execution simply continues.Otherwise,control returns to ________ until the result of the Task is available.Once the Task completes,the async method continues execution.

Accepted Answer

A)  the async method 
B)  the await clause 
C)  the async method's caller 
D)  the await method's caller

Question 3

When updating a control from a non-GUI thread,you must ________.

Accepted Answer

A)  launch a separate thread to perform the update 
B)  notify the GUI thread that you'll be updating it in another thread 
C)  ensure that the update doesn't corrupt the GUI thread's activities. 
D)  schedule that update to be performed by the GUI thread

Question 4

An async method executes its body in ________.

Accepted Answer

A)  the calling method 
B)  the called method 
C)  the main method 
D)  the same thread as the calling method

Question 5

Executing calculations in multiple threads on a single-core processor can actually take ________ compared to simply performing them synchronously,due to the overhead of sharing one processor among the app's threads,all the other apps executing on the computer at the same time and the chores the operating system was performing.

Accepted Answer

A)  less time 
B)  more time 
C)  about the same amount of time 
D)  much less time

Question 6

________ programming is a technique for writing apps containing tasks that can execute asynchronously,which can improve app performance and GUI responsiveness in apps with long-running or compute-intensive tasks.

Accepted Answer

A)  synchronous 
B)  object-oriented 
C)  task-oriented 
D)  Asynchronous

Question 7

Tasks that proceed independently of one another are said to execute ________ and are referred to as ________ tasks.

Accepted Answer

A)  synchronously, synchronous 
B)  independently, independent 
C)  asynchronously, asynchronous 
D)  intensively, intensive

Question 8

Which of the following statements is false

Accepted Answer

A)  ProgressBar property Minimum gets or sets a ProgressBar's minimum value. 
B)  ProgressBar property Maximum gets or sets a ProgressBar's maximum value. 
C)  ProgressBar property Value gets or sets a ProgressBar's current value. As this number increases, a ProgressBar fills with color. 
D)  None of the above is false.

Question 9

The _________ delegate represents any method that takes no arguments and returns a result.

Accepted Answer

A)  Func 
B)  async 
C)  task 
D)  TResult

Question 10

A ListBox's ________ property indicates the source of the data that populates the ListBox's Items collection.

Accepted Answer

A)  DataSource 
B)  DataOrigin 
C)  DataCreator 
D)  DataIssuer

Question 11

Class HttpClient's ________ method starts a new Task in a separate thread and uses the URL specified as the method's string argument to request information from a web server.

Accepted Answer

A)  RequestWebStringAsync 
B)  QueryWebStringAsync 
C)  StartTaskStringAsync 
D)  GetStringAsync

Question 12

A ListBox's ________ property indicates which property of each item in the data source should be displayed in the ListBox.

Accepted Answer

A)  ShowProperty 
B)  SelectProperty 
C)  DisplaySourceItem 
D)  DisplayMember

Question 13

An async method can perform other statements between those that launch an asynchronous Task and await the Task's results.In such as case,the method continues executing those statements after launching the asynchronous Task until it reaches ________.

Accepted Answer

A)  the await expression 
B)  the return statement 
C)  the Task return 
D)  the async return

Question 14

If a long-running calculation were to be performed synchronously in a GUI app,________.

Accepted Answer

A)  the GUI app would split off the long-running calculation into a separate thread. 
B)  the GUI would freeze until the calculation completed and the user would not be able to interact with the app 
C)  the app would terminate 
D)  the app would deadlock

Question 15

A method is declared async to indicate to the compiler that the method will ________.

Accepted Answer

A)  wait for a callback 
B)  perform a synchronous activity 
C)  create multiple threads 
D)  await an asynchronous task

Question 16

Many classes for web access,file processing,networking,image processing and more contain methods that return ________ objects for use with async and await,so you can take advantage of the asynchronous programming model.

Accepted Answer

A)  threads 
B)  Task 
C)  Transient 
D)  Token

Question 17

You can wait for multiple Tasks to complete by awaiting the result of Task static method ________.

Accepted Answer

A)  whenAny 
B)  WhenAll 
C)  when 
D)  whenTask

Exam 23: Asynchronous Programming With Async and Await

A MethodInvoker (namespace System.Windows.Forms) is a ________.