QUESTION 51
You need to register the reusable WinMD component. What should you do?

A.    Option A
B.    Option B
C.    Option C
D.    Option D

Answer: A

QUESTION 52
You need to modify the existing GetCurrentEnvironmentAsync() method in the Environment WinMD component to accept parameters.
Which type should you use at line CE07?

A.    dynamic
B.    List<string>
C.    Task<EnvironmentalStatus>
D.    IList<string>

Answer: C

QUESTION 53
The users need the ambient light readings at the time a goose sighting is made.
You need to set up the light-sensing device.
Which code segment should you add to the LoadSensors() method of the Environment class?

A.    Option A
B.    Option B
C.    Option C
D.    Option D

Answer: D
Explanation:
http://msdn.microsoft.com/en-us/library/windows/apps/br206408.aspx

QUESTION 54
You need to set the PlayTo source in the LoadFile() method.
Which line of code should you insert at line PT30?

A.    element.SetSource(videoFile, contentType);
B.    playToManager.SetSource(stream, contentType);
C.    dispatcher.SetSource(stream, contentType);
D.    element.SetSource(stream, contentType);

Answer: D

QUESTION 55
You need to ascertain whether the device that the app is running on has a compass.
Which line of code should you insert at line CE43?

A.    while(Windows.Devices.Sensors == Compass)
B.    if (Compass.GetDefault() != null)
C.    if (Compass.GetDefault() == Compass.FirstOrDefault)
D.    if (Compass.GetCurrentReading() != null)

Answer: B
Case Study 3: E-reader app (QUESTION 56 – QUESTION 68)
Background
You are developing a Windows Store style e-reader app.
Business Requirements
– Users must be able to upload e-books and documents and download them to e- reader devices.
– Users must be able to set a password to restrict access to their e-books and documents.
– Users must be able to create and store encrypted metadata about their e-books and documents.
– The app must replace system-generated error messages with custom-defined messages. These custom messages must come from a list of approved text.
– User actions such as printing pages, saving users’ current locations in documents, and taking notes should be enabled from buttons on an AppBar control.
– The app must provide trial functionality that will expire after 14 days. If the app expires while it is running, the app must display an expiration message to the user and prompt the user to purchase the app.
Technical Requirements
General:
– Configuration files must be read-only. All user settings must be stored in the Contoso Settings Service.
– The SocialPoller background task must run the code in the DoWork() method to collect content from the Contoso feed.
– The UI must always remain responsive to user actions.
Security
Secured e-book and document passwords must to be encrypted so that only the user who created the passwords can retrieve the metadata associated to the e- books and documents.
The system must log all exceptions through the auditing object and notify technicians of the issue.
Storage:
– The app must cache the next two chapters to the local device for users to read while disconnected from the network. This cache must be persisted if a reboot is performed.
– User state such as the current location in an e-book or document must be stored in the Microsoft SQL Azure database.
– User settings such as font sizes and colors must be stored through the Contoso Settings Service.
Network:
– Communication between the app and e-book vendors must occur over an encrypted communication channel.
– Communication must use certificates to enable the SSL connection.
Trial Functionality:
– The isPrintEnabled variable must determine if the user can print.
– The isMarketEnabled variable must determine if the user can use the marketplace.
– The isTrialEnabled variable must determine if the application is still in trial mode.
Printing:
– The default printing options are portrait orientation and grayscale color mode.
– The app must enable the user to select the media size and printing orientation.
SocialPoller.es

Auditor.cs

ContentPage.es

Book.cs

Book.cs

SocialPost.es

Pagel.xaml.es

App.xaml.cs

QUESTION 56
Drag and Drop Question
You need to call the DoWork() method asynchronously in a background task.
Which four lines of code should you use to create the Run() method on line SP13? (To answer, move the appropriate lines of code from the list of code segments to the answer area and arrange them in the correct order.)

Answer:

QUESTION 57
You need to update the DoWork() method of the background task to meet the requirements.
What should you do? (Each correct answer presents part of the solution. Choose all that apply.)

A.    Get the IsCancellationRequested property from the CancellationToken object and return a Task
CompletionSource object.
B.    Access the Progress object and report the task’s progress to the caller.
C.    Update the DoWork() method to receive a Progress object.
D.    Add the CancellationToken object to the client.GetAsync() method.
E.    Confirm that the IsCancellationRequested property of the CancellationToken object is true and exit
the task.
F.    Update the DoWork() method to receive a CancellationToken object in the arguments of the method.

Answer: DEF
Explanation:
Cancellation is controlled by the CancellationToken structure.
You expose cancellation tokens in the signature of cancelable async methods, enabling them to be shared between the task and caller. In the most common case, cancellation follows this flow:
(D) The caller creates a CancellationTokenSource object.
(F) The caller calls a cancelable async API, and passes the CancellationToken from the CancellationTokenSource (CancellationTokenSource.Token). The caller requests cancellation using the CancellationTokenSource object (CancellationTokenSource.Cancel()).
(E)The task acknowledges the cancellation and cancels itself, typically using the CancellationToken.ThrowIfCancellationRequested method.
* From scenario:
/ The SocialPoller background task must run the code in the DoWork() method to collect content from the Contoso feed.
/ The UI must always remain responsive to user actions.
Note:
* Task-based Asynchronous Pattern
* CancellationToken Structure
/ Propagates notification that operations should be canceled.
/ CancellationToken. IsCancellationRequested
Gets whether cancellation has been requested for this token.

QUESTION 58
You need to enable the capabilities that allow communication according to the technical requirements.
Which capabilities should you enable? (Each correct answer presents part of the solution.
Choose all that apply.)

A.    Shared User Certificates
B.    SSL Certificates
C.    Internet (Client)
D.    Default Windows Credentials

Answer: BC
Explanation:
B: From scenario:
Communication between the app and e-book vendors must occur over an encrypted communication channel.
Communication must use certificates to enable the SSL connection.
C:

QUESTION 59
Drag and Drop Question
You need to ascertain whether the app trial period has expired.
You have the following code that you plan to insert at line AX22 of App.xaml.cs:

Which code snippets should you include in Target 1 and Target 2 to complete the code? (To answer, drag the appropriate code snippets to the correct targets in the answer area. Each code snippet may be used once, more than once, or not at all. You may need to drag the split bar between panes or scroll to view content.)

Answer:

QUESTION 60
You need to handle the following exception and meet the error handling requirements.

Which code segment should you use?

A.    Option A
B.    Option B
C.    Option C
D.    Option D

Answer: A