Lecture 12: Intro to Services

Question 1

A service is launched from the __ as the __ that called it

Answer 1

• same thread
• host

Question 2

Can services run in parallel?

Answer 2

No

Question 3

Services have a lifetime that may be controlled by the ___ or __

Answer 3

• service itself
• outside forces

Question 4

What are the 2 broad categories services can be split into based on their user visibility

Answer 4

• foreground services
• background services

Question 5

A __ service doesnt require user UI interaction, but does require that a notification be shown to let the user know the serivce is running

Answer 5

foreground

Question 6

A __ service a a hidden service. Not required to provide a notification or provide any indication that its running

Answer 6

background

Question 7

__ services are good for silently updating or managing aspects of your app without requiring user interaction

Answer 7

background

Question 8

What are some of the limitations you may do with background services since they provide no indication that theyre running

Answer 8

• Give them a allowance of time to access sensitive info since the last user noticeable action
• May be restricted from using certain components

Question 9

When are bound services essential?

Answer 9

When a service must be able to pass data off to other activities or services in real time rather than editing data on disk for others to read

Question 10

A __ service creates a communication link between itself and one or more binders that allows for data transfer back and forth

Answer 10

bound

Question 11

What 3 things do you need to create a service?

Answer 11

• An entry in the app manifest file declaring the service with a name and other descriptors
• A java class that extends the standard service class for android and implements the 4 lifecycle functions required
• An intent used to launch the service

Question 12

Services must be declared within your app manifest within a __ tag and the only required field is the ___

Answer 12

• <service>
  </service>
• name of the service

Question 13

Each service is defined it its own __ which ___ from the default Android ___ class

Answer 13

• class
• extends
• service

Question 14

Within the service class we must __ a set of __ for the service

Answer 14

• override
• lifecycle functions

Question 15

Describe the service lifecycle

Answer 15

• Begins with onCreate() and ends with onDestroy()

Question 16

Unbound services are called with a __ and call the __ method

Bound services use __ and call on the __ and __

Answer 16

startService(), onStartCommand()

bindService(), onBind(), onUnbind()

Question 17

We can think of each lifecycle function as being some block of code we want to execute at a __ of the __

Answer 17

• very specific stage
• services life

Question 18

When a service terminates depends on the ___

an __ will run ___ if allows

Answer 18

service type

unbound service, indefinitely

Question 19

Started or unbound services must use ___ to terminate themselves when they have ___

Answer 19

stopSelf()

completed their tasks

Question 20

Bound services will automatically be __ when all ___ are ___

Answer 20

destroyed

bound components, unbound

Question 21

What does the constant startMode do?

Answer 21

An int value that tells the system how to handle unexpected termination

Question 22

What does START_NOT_STICKY tell the system?

Answer 22

Not to restart your service after exiting

Question 23

What does START_STICKY tell the system?

Answer 23

To restart the service but with a null intent

Question 24

What does START_REDELIVER_INTENT tell the system?

Answer 24

Restart and resend the original intent when launching the service

Question 25

What is the safest way to tell the system to handle unexpected termination and why?

Answer 25

START_NOT_STICKY

Ensures service wont be dangling doing nothing

Question 26

How do you start a service in unbound mode?

Answer 26

Create an intent pointing to the service class and pass it to startService()