1. What are the key components of Android
Architecture?
Android
Architecture consists of 4 key components:
·
Linux
Kernel
·
Libraries
·
Android
Framework
·
Android
Applications
2. What are the advantages of having an emulator
within the Android environment?
·
The
emulator allows the developers to work around an interface which acts as if it
were an actual mobile device.
·
They
can write, test and debug the code.
·
They
are safe for testing the code in early design phase
3. Tell us something about activityCreator?
·
An
activityCreator is the initial step for creation of a new Android project.
·
It
consists of a shell script that is used to create new file system structure
required for writing codes in Android IDE.
4. What do you know about Intents?
·
Notification
messages to the user from an Android enabled device can be displayed using
Intents. The users can respond to intents.
·
There
are two types of Intents - Explicit Intent, Implicit Intent.
5. What is an Explicit Intent?
·
Explicit
intent specifies the particular activity that should respond to the intent.
·
They
are used for application internal messages.
6. What is an Implicit Intent?
·
In
case of Implicit Intent, an intent is just declared.
·
It
is for the platform to find an activity that can respond to it.
·
Since
the target component is not declared, it is used for activating components of
other applications.
7. What do intent filters do?
·
There
can be more than one intents, depending on the services and activities that are
going to use them.
·
Each
component needs to tell which intents they want to respond to.
·
Intent
filters filter out the intents that these components are willing to respond to.
8. Where are lay out details placed? Why?
·
Layout
details are placed in XML files
·
XML-based
layouts provide a consistent and standard means of setting GUI definition
format.
9. What do containers hold?
·
Containers
hold objects and widgets in a specified arrangement.
·
They
can also hold labels, fields, buttons, or child containers. .
10. What is Orientation?
·
Orientation
decides if the LinearLayout should be presented in row wise or column wise
fashion.
·
The
values are set using setOrientation()
·
The
values can be HORIZONTAL or VERTICAL
11. What is it important to set permissions in
app development?
·
Certain
restrictions to protect data and code can be set using permissions.
·
In
absence of these permissions, codes could get compromised causing defects in
functionality.
12. What is AIDL?
·
AIDL
is the abbreviation for Android Interface Definition Language.
·
It
handles the interface requirements between a client and a service to
communicate at the same level through interprocess communication.
·
The
process involves breaking down objects into primitives that are Android
understandable.
13. What data types are supported by AIDL?
AIDL supports
following data types:
·
string
·
List
·
Map
·
charSequence
·
all
native Java data types like int,long, char and Boolean
14. Tell us something about nine-patch image.
·
The
Nine-patch in the image name refers to the way the image can be resized: 4
corners that are unscaled, 4 edges that are scaled in 1 axis, and the middle
one that can be scaled into both axes.
·
A
Nine-patch image allows resizing that can be used as background or other image
size requirements for the target device.
15. Which dialog boxes are supported by
android?
Android supports
4 dialog boxes:
a.) AlertDialog:
Alert dialog box supports 0 to 3 buttons and a list of selectable elements
which includes check boxes and radio buttons.
b.) ProgressDialog:
This dialog box is an extension of AlertDialog and supports adding buttons. It
displays a progress wheel or bar.
c.)
DatePickerDialog: The user can select the date using this dialog box.
d.)
TimePickerDialog: The user can select the time using this dialog box.
16. What is Dalvik Virtual Machine?
·
It
is Android's virtual machine.
·
It
is an interpreter-only virtual machine which executes files in Dalvik
Executable (.dex) format. This format is optimized for efficient storage and
memory-mappable execution.
