Android Development
Content
Android: Android Android: Android is an open-source software stack that includes the operating operating system, middleware, and key mobile applications, along with a set of API libraries for writing applications that can shape the look, feel and functions of the devices which they run. Android is an ecosystem made up of a combination of three components:
A free, open-source operating system for embedded devices
An open-source development platform for creating applications applications
Devices, particularly mobile phones, that run the Android operating system and the applications created for it
Some Mobile Platforms
Android – developed by Google.
iOS – developed by Apple .
Symbian – developed by Nokia 2008
Windows Phone 7 – developed by Microsoft
Blackberry OS – developed by RIM (Research in Motion)
Q. What are important features of android? Android is made up of several necessary and dependent parts, including including the following:
A Compatibility Definition Document (CDD) and Compatibility Test Suite (CTS) that describe the capabilities required for a device to support the software stack.
A Linux operating system kernel that provides a low-level interface with the hardware, memory management, and process control, all optimized for mobile and embedded devices.
Open-source libraries for application development, including SQLite, WebKit, OpenGL, and a media manager.
A run time used to execute and host Android applications, including the Dalvik
Virtual Machine (VM) and the core libraries that provide Android-specific functionality. The run time is designed to be small and efficient for use on mobile devices.
An application framework that agnostically exposes system services to the application layer, including the window manager and location manager, databases, telephony, and sensors.
A user interface framework used to host and launch launch applications.
A set of core pre-installed applications.
A software development kit (SDK) used to create applications, including the related tools, plug-ins, and documentation.
1|Page
Q. Why android is so popular? Global partnerships and large installed base: Building on the contributions of the open-source Linux community and more than 300 hardware, software, and carrier partners, Android has rapidly become the fastest-growing mobile OS. OS. Powerful development framework: Easily optimize a single binary for phones, tablets, and other devices. devices. Open marketplace for distributing apps: Google apps: Google Play is the premier marketplace for selling and distributing Android apps. When you publish an app on Google Play, you reach the huge installed base of Android. Android. Q. Write name of some native android application Native Android Applications: Android devices typically come with a suite of preinstalled applications that form part of the Android Open Source Project (AOSP), including, but not necessarily limited to, the following: fol lowing:
An e-mail client
An SMS management application
A full PIM (personal information management) suite, including a calendar and contacts list
A WebKit-based web browser
A music player and picture gallery
A camera and video recording application
A calculator
A home screen An alarm clock In many cases Android devices also ship with the following proprietary Google mobile applications:
The Google Play Store for downloading third-party Android applications
A fully featured mobile Google Maps application, including StreetView, driving directions, and turn-byturn navigation, satellite views, and traffic conditions
The Gmail email client
The Google Talk instant-messaging client
The YouTube video player
2|Page
Q. What platforms don't have? have? Q. What Android has that other platforms The following non comprehensive list details some of the features available on Android that may not be available on all modern mobile development platforms: Google Maps applications— applications—Google Maps for Mobile has been hugely popular, and Android offers a Google Map as an atomic, reusable control for use in your applications. applications. Background services and applications— applications—Full support for background applications and services lets you create applications based on an event-driven model, working silently while other applications are being used or while your mobile sits ignored until it rings, flashes, or vibrates to get your attention. Shared data and inter-process communication— communication— Using Intents and Content Providers, Android lets your applications exchange messages, perform processing, and share data. All applications are created equal— equal— Android doesn't differentiate between native applications and those developed by third parties. Wi-Fi Direct and Android Beam— Beam—Using these innovative new inter-device communication APIs, you can include features such as instant media sharing and streaming. Home-screen Widgets, Live Wallpaper, and the quick search box— box —Using Widgets and Live Live Wallpaper, you can create windows into your your application from the phone's home screen. The quick search box lets you integrate search results from your your application directly into the phone's search search functionality. functionality. Android Application Architecture Architecture Android's architecture encourages component reuse, enabling you to publish and share Activities, Services, and data with other applications, with access managed by the security restrictions you define. The same mechanism that enables you to produce a replacement contact manager or phone dialler can let you expose your application's components in order to let other developers build on them by creating new UI front ends or functionality extensions. The following application services are the architectural cornerstones of all Android applications, providing the framework you'll be using for your own software: Activity Manager and Fragment Manager Manager— — Control the lifecycle of your Activities and Fragments, respectively, including management of the Activity stack (described in Chapters 3 and 4). Views— Views —Used to construct the user interfaces for your Activities and Fragments, as described in Chapter 4. 3|Page
Notification Manager— Manager—Provides a consistent and nonintrusive mechanism for signalling your users, as described in Chapter 10. Content Providers— Providers—Lets your applications share data, as described in Chapter 8. Resource Manager— Manager—Enables non-code resources, such as strings and graphics, to be externalized, as shown in Chapter 3. Intents— Intents —Provides a mechanism for transferring data between applications and their components, as described in Chapter 5. Types of Android Applications Most of the applications you create in Android will fall into one of the following categories: Foreground— Foreground — An application that's useful only when it's in the foreground and is effectively suspended when it's not visible. Games are the most common examples. Background— Background — An application with limited interaction that, apart from when being configured, spends most of its lifetime hidden. These applications are less common, but good examples include call screening applications, SMS auto-responders, and alarm clocks. Intermittent—Most well-designed applications fall into this category. At one extreme Intermittent— are applications that expect limited interactivity but do most of their work in the background. A common example would be a media player. At the other extreme are applications that are typically used as foreground applications but that do important work in the background. Email and news applications applications are great examples. Widgets and Live Wallpapers— Wallpapers—Some applications are represented only as a homescreen Widget or as a Live Wallpaper. Complex applications are often difficult to pigeonhole into a single category and usually include elements of each of these types. When creating your application, you need to consider how it's likely to be used and then design it accordingly. The following sections look more closely at some of the design considerations for each application type. Android Emulator: The emulator is a tool for testing and debugging applications, particularly when we don’t have a real device for experimentation. experimentation. Android applications applications consist of loosely coupled components, bound by the application manifest that describes each component and how they interact. The manifest is also used to specify the application's metadata, its hardware and platform requirements, external libraries, and required permissions. The following components comprise the building blocks for all your Android applications: Activities— Your application's presentation layer. The UI of your application is built Activities— around one or more extensions of the Activity class. Activities use Fragments and Views 4|Page
to layout and display information, and to respond to user actions. Compared to desktop development, Activities are equivalent to Forms. You'll learn more about Activities later in this chapter. Services— Services —The invisible workers of your application. Service components run without a UI, updating your data sources and Activities, triggering Notifications, and broadcasting Intents. They're T hey're used to perform long running tasks, or those that require no user interaction (such as network lookups or tasks that need to continue even when your application's Activities aren't active or visible.) You'll learn more about how to create and use services in Chapter 9, “Working in the Background.” Content Providers— Providers—Shareable persistent data storage. Content Providers manage and persist application data and typically interact with SQL databases. They're also the preferred means to share data across application boundaries. You can configure your application's Content Providers to allow access from other applications, and you can access the Content Providers exposed by others. Android devices include several native Content Providers that expose useful databases such as the media store and contacts. You'll learn how to create and use Content Providers in Chapter 8, “Databases and Content Providers.” Intents— Intents — A powerful inter application message passing framework. Intents are used extensively throughout Android. You can use Intents to start and stop Activities and Services, to broadcast messages system-wide or to an explicit Activity, Service, or Broadcast Receiver, or to request an action be performed on a particular piece of data. Explicit,
implicit,
and
broadcast
Intents
are
explored
in
more
detail in Chapter 5, “Intents and Broadcast Receivers.” Broadcast Receivers— Receivers—Intent listeners. Broadcast Receivers enable your application to listen for Intents that match the criteria you specify. Broadcast Receivers start your application to react to any received Intent, making them perfect for creating event driven applications. Broadcast Receivers are covered with Intents in Chapter 5. Widgets— Widgets — Visual application components that are typically added to the device home screen. A special variation of a Broadcast Receiver, widgets enable you to create dynamic, interactive application components for users to embed on their home screens. You'll learn how to create your own widgets in Chapter 1 4, “Invading the Home Screen.” Screen.” Notifications— Notifications —Notifications enable you to alert users to application events without stealing focus or interrupting their current Activity. They're the preferred technique for getting a user's attention when your application is not visible or active, particularly from within a Service or Broadcast Receiver. For example, when a device receives a text message or an email, the messaging and Gmail applications use Notifications to alert 5|Page
you by flashing lights, playing sounds, displaying icons, and scrolling a text summary. You can trigger these notifications from your applications, as discussed in Chapter 1 0, “Expanding the User Experience.” By decoupling the dependencies between application components, you can share and use individual Content Providers, Services, and even Activities with other applications applications— — both your own and those of third third parties.
Android questions and Answers
1.
bmgr
a)take
tool
backup
is of
b)to
used the
applications
restore
c)wipe
archived
data
to operations
for
a
specific
application
d)all of the above
ans:
d
2.
foreground
a)starts b)may
when or
may
you not
provide
call a
notification
service start for
foreground() the
status
bar
c)notification can't be dismissed unless the service is either stopped or removed from the 6|Page
foreground d)both
a
&
c
ans:d
3. A1,A2,A3 and A4 are activities called using intents.Then A1-A4-A2--A3.A4 calls A2 with intent flag FLAG_ACTIVITY_NO_HISTORY.When FLAG_ACTIVITY_NO_HISTORY.When finish method is ccalled alled on A3, What will currtent
be running
the activity?
a)A1 b)A4 c)A3 d)A2 ans:
b
4. A1,A2,A3 and A4 are activities called using intents.Then A1-A2-A4--A3.A2 calls A4 with intent flag FLAG_ACTIVITY_CLEAR_TOP.When finish() method is called on A3, what will current
be running
the activity?
a)A4 b)A3 c)A2 d)A1 Ans:
a
5. A1,A2,A3 and A4 are activities called using intents.Then A1-A2-A3-A4. A3 calls A4 with
no
intent flag, when finish() method called on A4. What will be the current running activity? a)A2 7|Page
b)A3 c)A4 d)A1 Ans:
6.
b
The
a) b) c)
plus(+)
means
Identify Create XML
it new
parser
d)
in
statement as
id
android:id="@+id/my_id"?
an and
should
add
parse
Both
id to
and
resource resources
exapnd
a
id
&
string b.
Ans:
b
7. When you want system to run the service indefinitely, by restarting it when get killed, use a) b)
START_NOT_STICKY START_REDELIVER_INTENT START_REDELIVER_INTEN T
c)
START_STICKY
d)
START_SERVICE_INDEFINITELY
Ans:
c
8)
Android
system
uses
intents
to
a)
broadcast
system
intents
b)
broadcast
custom
intents
c) d)
To
invoke All
other
applications of
from the
your
Ans: 9)
application. above. d
'Screen
has
turned
off'
is
an
example
a) b)
Normal Ordered
broadcast broadcast
c) d)
background
operation None
8|Page
Ans:
a
10) If you try to acces the column which does not exit,
system throws
a)
NullPointerException
b)
illegalArgumentException
c) d)
ArrayIndexOutOfBoundsException SQLException
Ans: 11)
b Maximum
results
returned
by
getFromLocationName()
method
can
be
a)
2
b)
3
c) d)
4 5
Ans:
d
12. The methods startForeground() and stopForeground() were introduced in which API
level.
a)
2.0
b)
3.0
C)
1.5
d)
2.2
Ans:
a
13. Should always first check availability of audio effects by calling the following method on the
corresponding
audio
effect
class.
a)
ischeckable()
b) c)
isavailable() ()
9|Page
isvaluable
d)
iscaview()
Ans:
a
14. Applications that require filtering based on screen size can use the attributes.
a) b)
<supportmultiple-screens> <supports-screens>
c) d)
<supportall-screens supportevery-screen
Ans:
b
15. a) b)
what is
c) d)
called calling
if if
you you
is
false
when another startService() don't want
with
respect
component results
wants to in a
want to allow to allow binding
to bind call
with to
onBind() a
service onBind()
binding then return null then return Ibinder object
Ans: b
Android Objective type Question and Answers Android
Objective
type
Question
and
Answers
1) Once installed on a device, each Android application lives in_______? a)device memory b)external
memory
c) d)None
security of
sandbox the
Ans) 2)Parent a)Object b)Context c)ActivityGroup d)ContextThemeWrapper 10 | P a g e
above c
class
of
Activity?
Ans) 3)What
d are
the
Direct
subclasses
of
Activity?
a)AccountAuthenticatorActivity b)
ActivityGroup
c)
ExpandableListActivity
d) e)
FragmentActivity ListActivity
f) Ans) 4)What
all
are
the
the
indirect
Direct
aove f
subclasses
of
Activity?
a)LauncherActivity b)PreferenceActivity c)
TabActivity
d)All Ans)
the
5)Parent a)Object
above d
class
of
Service?
b)Context c)
ContextWrapper
d)ContextThemeWrapper Ans) 6)What
c are
the
indirect
Direct
subclasses
of
Services?
a)
RecognitionService
b)
RemoteViewsService
c)SpellCheckerService d)InputMethodService Ans) 7)Which
component
is
not
activated
by
an
d Intent?
a)Activity b)Services c)ContentProvider d)BroadcastReceiver Ans) 8)When a)Using b)Using c)Using 11 | P a g e
c contentProvider
would
be
activated? Intent SQLite ContentResolver
d)None
of
the
above
Ans)
c
9)Which of the important device characteristics characteristics that you should consider as you design and
develop
a)Screen
your
size
application?
and
density
b)Input
configurations
c)Device d)Platform
features Version
e)All Ans)
of
10)Which
are
the
the
screen
above e
sizes
in
Android?
a)small b)normal c)large d)extra
large
e)All Ans)
of
11)Which a)low
are
the
the
screen
above e
densities
in
Android? density
b)medium
density
c)high
density
d)extra
high
e)All Ans)
density
of
12)You
can
shut
down
the an
activity
by
above e
calling
its
_______
method
a)onDestory() b)finishActivity() c)finish() d)None
of
the
above
Ans) c 13)What is the difference between Activity context and Application Context? a)
The
Activity
instance
is
tied
to
the
lifecycle
of
an
Activity.
while the application instance is tied to the lifecycle of the application, b)
The
Activity
instance
is
tied
to
the
lifecycle
of
the
application,
while the application instance is tied to the lifecycle of an Activity. c)
The
Activity
instance
is
tied
to
the
lifecycle
of
the
Activity,
while the application instance is tied to the lifecycle of an application. d) None of the above Ans) 14)Which 12 | P a g e
one
is
NOT
related
to
fragment
a class?
a)DialogFragment b)ListFragment c)PreferenceFragment d)CursorFragment Ansa)d 15)Definition
of
Loader?
a) loaders make it easy to asynchronously load data in an activity or fragment. b) loaders make it easy to synchronously load data in an activity or fragment. c) loaders does not make it easy to asynchronously load data in an activity or fragment. d) None of the above. Ans)
a
16)Characteristics a)They
of
are
b)They
available
the
to
provide
every
Loaders?
Activity
asynchronous
and
loading
Fragment. of
data.
c)They monitor the source of their data and deliver new results when the content changes. d)They automatically reconnect to the last loader's cursor when being recreated after a configuration e)All
change.
Thus, of
they
don't
need to the
re-query
Ans)
their
data. above. e
17)How
many
ways
to
start
services?
a)Started b)Bound c)a
&
d)None
of
b the
above.
Ans)
c
18)If your service is private to your own application and runs in the same process as the client (which is common), you should create your interface by extending the ________class? a)
Messenger
d)None
b)
Binder
c)
AIDL of
the
above
Ans)
b
19)If you need your interface to work across different processes, you can create an interface
for
the
service
with
a
________? a)Binder b)Messenger c)AIDL
13 | P a g e
d)
b
or
c
Ans)
d
20)AsyncTask allows you to perform asynchronous work on your user interface. It performs the blocking operations in a worker thread and then publishes the results on the
UI
thread. a)true b)false a
Ans) 21)Layouts a)Frame
in
android? Layout
b)Linear
Layout
c)Relative
Layout
d)Table
Layout
e)All
of
the
above
Ans) 22)
e Dialog
classes
in
android? a)AlertDialog b)ProgressDialog c)DatePickerDialog d)TimePickerDialog
e)All
of
the
above
Ans)
e
23)If you want share the data accross the all applications ,you should go for? a)Shared Preferences b)Internal
Storage
c)SQLite
Databases
d)content Ans) 24)Difference
between
android
provider api
and
d api?
a)The google API includes Google Maps and other Google-specific libraries. The Android one only includes core android libraries. b)The google API one only includes core android libraries. The Android includes Google
Maps c)None
and
other of
Google-specific the
libraries. above.
Ans) a Android: Menus and Dialogs
Table 1. 1. Menus Menus 14 | P a g e
of
contents:
Options menu Context menu Sub menu Creating different Menus 2. Dialogs Alert Dialog Progressbar dialog DatePicker dialog TimePicker Dialog Toast Creating different dialogs Menus Menus provide familiar interfaces to expose application functions without sacrificing screen space. Android offers an easy programming interface to provide standardized application menus. Android offers three fundamental types types of application menus: Options Menu Context Menu Sub-menu
Options
Menu:
By default, every Activity supports an Options menu of actions or options. It is revealed by pressing the device MENU key. Options Menu has two groups of menu items: Icon Menu 15 | P a g e
Collection of maximum of six menu items Supports Icons and short-cuts Expanded Menu Exposed by the 'More' menu item Displayed when the icon menu becomes over-loaded Comprised of sixth options menu item and the rest.
16 | P a g e
Create Options Menu: Following methods are provided by Activity class to create an Options menu : 1 2 3
public public
public
boolean boolean
onCreateOptionsMenu(Menu onCreateOptionsMenu(Menu
menu)
onPrepareOptionsMenu(Menu
menu)
boolean onOptionsItemSelected(MenuItem onOptionsItemSelected(MenuItem
item)
4 Override onCreateOptionsMenu() callback method, to add items to Options menu using menu.add() method. 17 | P a g e
menu.add() adds a MenuItem and returns the newly created object to set additional properties like icon, shortcut, ...etc. public abstract MenuItem add(groupId, itemId, order, CharSequence) Override onOptionsItemSelected() callback method to perform any action for a selected Options menu item by identifying its id using item.getItemId(). public abstract int getItemId() Override onPrepareOptionsMenu() callback method to update the menu dynamically each time it gets displayed.
Options Menu Life Cycle:
Options /* public
Menu Creates
the
boolean
Example: menu
items
onCreateOptionsMenu(Menu
menu)
*/ {
menu.add(0,
1,
0,
"Menu
1");
menu.add(0,
2,
0,
"Menu
2");
return } /* 18 | P a g e
true; Handles
item
selections
*/
public
boolean
onOptionsItemSelected(MenuItem
switch
item)
{
(item.getItemId())
case
1:
//Action
{
for
Menu
1
return
true;
case
2:
//Action
for
Menu
2
return
true;
} return
false;
}
/*
Re-write
public //Action
the
Options
boolean to
SubMenu
Menu
as
it
is
onPrepareOptionsMenu(Menu
modify
Menu
sm1
each =
time
opened menu)
it
is
*/ {
opened.
(SubMenu)menu.getItem(0);
sm1.setIcon(R.drawable.icon); sm1.add("NM
X");
menu.getItem(4).setIcon(R.drawable.icon); return
super.onPrepareOptionsMenu(menu);
}
Sub
Menu:
Sub menu is a floating menu, it can be a child menu of options menu or context menu. It supports
checkboxes,
radio
buttons
It does not support item icons, or nested sub menus.
19 | P a g e
and
shortcut
keys.
Context Menu Context menu is a floating menu that is associated with a control. Context menu is launched when the control has the focus and the D pad is pressed. Context menus can be assigned to any View within an Activity. It provides functions relating to the view, to which it is registered. It supports submenus, checkboxes, radio buttons. It does not support shortcuts and icons.
20 | P a g e
Create
Context
Menu:
Methods provided by Activity class to create and register an Context menu are : public void onCreateContextMenu(ContextMenu, onCreateContextMenu(ContextMenu, View, ContextMenuInfo) public boolean onContextItemSelected(MenuItem item) public void registerForContextMenu(view) Override onCreateContextMenu() callback method, to add items to Context menu using menu.add() method. menu.add() adds a MenuItem and returns the newly created object to set properties like checkboxes, radio buttons ...etc. Override onContextItemSelected() callback method to perform any action for a selected item by its id using item.getItemId(). Call registerForContextMenu(view) method inside onCreate() method to register the context menu for a view.
Context Menu Life Cycle:
21 | P a g e
Context
Menu
/*
Register
a
Example: view
to
public void onCreate(Bundle super.onCreate(savedInstanceState); Button
update
*/
savedInstanceState){
=
new
Button(this);
update.setText(“UPDATE”); update.setText(“UPDATE”); setContentView(update); registerForContextMenu(update); } /*
Create
a
Context
Menu
*/
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo)
{
super.onCreateContextMenu(menu,
v,
menu.add(0, menu.add(0,
0, 0,
1, 2,
menuInfo); "Edit"); "Delete");
} /*
Action
public
boolean
on
1:
//Action
case
2:
//Action
return
} 22 | P a g e
for for
menu Menu
*/ item)
(item.getItemId())
case return
}
selection
onContextItemSelected(MenuItem
switch
default:
item
{ {
item item
“Edit” “Edit” true; “Delete” “Delete” true;
return
super.onContextItemSelected(item);
Context
sub
Menu:
Menu class provides a method named addSubMenu() to add sub menus under an Options menu or a Context menu. public abstract SubMenu addSubMenu(group, item, order, String) Submenu.add() method is used to add sub-menu items. onOptionsItemSelected() callback method for a SubMenu item refers to it's parent's callback method. Inside onOptionsItemSelected() callback the state of the radio button/ checkbox must be set, if the submenu item item is a radio button or checkbox.
Dialog:
A dialog is a small window that appears in front of an an Activity. The underlying Activity loses focus and the dialog accepts all user interaction. Normally used for notifications and short activities that directly relate to the application in progress. Android supports following types of dialogs. 1 2
Alert
Dialog
Progress
Dialog
3
Date
Picker
Dialog
4
Time 5
Picker
Dialog Toast
Alert Dialog: A dialog that can manage zero, one, two or three buttons. It can also manage a list of selectable items that can include checkboxes or radio buttons. The AlertDialog is capable of constructing most dialog user interfaces and is the suggested dialog type. AlertDialog class is a subclass of Dialog class and has a nested subclass 23 | P a g e
AlertDialog.Builder to construct a dialog. dialog.
Other Dialogs: Progress Dialog A dialog that displays a progress wheel or progress bar. It supports buttons like in AlertDialog. DatePicker Dialog A dialog that allows the user to select a date. date. TimePicker Dialog A dialog that allows the user to select a time.
Toast:
A toast is a transient Dialog box containing containing a quick little message for the user. Toasts never receive focus and they don’t interrupt the active application. application. They provide an ideal mechanism for alerting users to events occurring in background Services without interrupting foreground applications. Toast class provides a static method to create a standard toast display d isplay window. static Toast makeText(context, text, duration) Examples : Volume control, message for change settings.
Create
A dialog is always created and displayed as a part of an Activity. Activity. Activity provides following methods to create and and display dialogs, onCreateDialog(int id) onPrepareDialog(int id, Dialog dialog) showDialog(int id) 24 | P a g e
Dialog:
Override the onCreateDialog(int id) callback method to create a dialog. Override the onPrepareDialog(id, dialog) callback method to populate the dialog over the screen each time it gets displayed. Call the showDialog(int id) method to display a dialog.
Dialog Life Cycle:
Create
Dialog:
Override
onCreateDialog(id)
protected
Dialog
to
create
a
onCreateDialog(int
dialog
id)
{
switch(id){ case
DIALOG_ALERT_ID:
//Create
required
case //Create
dialog
required
dialog
and
return
and
DIALOG_DISP: return object
case
object
DIALOG_PROGRESS:
//Create
required
dialog
and
return
object
default: return
super.onCreateDialog(id);
} Call
showDialog(id)
to
display
the
corresponding
dialog
showDialog(DIALOG_PROGRESS); Override protected
onPrepareDialog() void
onPrepareDialog(int
super.onPrepareDialog(id, 25 | P a g e
to
modify id,
Dialog
a
dialog dialog)
{
dialog);
switch(id)
{
case
DIALOG_ALERT_ID:
//Modify
in
dialog
and
break;
case
DIALOG_DISP:
//Modify
in
dialog
and
case
break;
DIALOG_PROGRESS:
//Modify default
in
dialog
and
break; :
break; } } Create
Alert
Create a dialog AlertDialog.Builder
builder using builder
Set all required builder.setMessage(“message
Dialog:
AlertDialog.Builder by passing context. = new AlertDialog.Builder(this);
properties
for
the
created
to
.setTitle(“title
to
builder. display”) display”) display”) display”)
.setCancelable(false); //Can
set
different
setPositiveButton("Yes", //override onClick()
buttons
here
new DialogInterface.OnClickListener() { and perform required operation like finish()
} setNegativeButton("No", //override
onClick()
}) Retrieve
the
new and
Alert
AlertDialog
ProgressDialog
perform
required
dialog
object
alertObj
Create
Create
DialogInterface.OnClickListener() operation with
=
like
builder.create(); Dialog:
progress progress
=
dialog new
26 | P a g e
Please
object
ProgressDialog(mContext);
Set all the required properties and progress.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); progress.setTitle("Loading..."); progress.setMessage("Loading.
cancel()
builder.create().
Progress
a
{
return
wait...");
progress.setCancelable(false); Create
the
object
ProgressDialog
by
its
dialog
"Loading.
show()
=
method,
set
shown
ProgressDialog.show(this,
Please
//Can
as
"Loading...",
wait...",
other
below. true);
properties
here
also
dialog.setCancelable(true); dialog.setIcon(R.drawable.icon); Create
Time
Picker
Dialog:
Create a TimePickerDialog object by passing context and other parameters, as shown
below.
//Get
the
final
Calendar
c
mHour mMinute //Create return public
current =
=
new void
return the TimePickerDialog(this,
onTimeSet(TimePicker
//Perform
TimePickerDialog object new OnTimeSetListener() {
view,
operation
}},
int
hourOfDay,
on
mHour,
Create
Calendar.getInstance(); c.get(Calendar.HOUR_OF_DAY); c.get(Calendar.MINUTE);
= and
Time
int
time
minute)
{ set
mMinute,
true);
picker
dialog:
Date
Create a DatePickerDialog object by passing context and other parameters, as shown below. //Get final mYear
the Calendar
c
mMonth mDay //Create
current =
=
Calendar.getInstance(); c.get(Calendar.YEAR);
=
c.get(Calendar.MONTH);
= and
Date
return
c.get(Calendar.DAY_OF_MONTH); the
DatePickerDialog
object
return new DatePickerDialog(this, new DatePickerDialog.OnDateSetListener() { public int //Perform } }, 27 | P a g e
void
onDateSet(DatePicker
monthOfYear, operation mYear,
view,
int on mMonth,
int
dayOfMonth) date
year, { set mDay);
Create
Toast:
Create
a
Toast
Toast
t
object =
with
new
t.setText("Dialog t.setGravity(Gravity.LEFT, a
duration
Displayed 10, 100);
Toast
context.
Toast(getApplicationContext());
Set properties like text, t.setDuration(Toast.LENGTH_LONG);
Display
application
and
from //Position, xOffset
using
its
show()
method
makeText()
position. Toast"); yOffset
and
method.
t.show(); Create Toast
directly t
=
using
its
static
Toast.makeText(getApplicationContext(),
as
below.
"Dialog
Displayed",
used
to
Toast.LENGTH_SHOT);
Android Questions and Answers for written exams exams
1.
bmgr
a)take
tool
backup
is of
b)to
the
applications
restore
c)wipe
archived
d)all
data
operations
for
a
of
specific the
above
ans:
d
2. a)starts b)may
application
foreground or
when may not
you provide
a
service
call start notification for
the
foreground() status bar
c)notification can't be dismissed unless the service is either stopped or removed from the foreground d)both
a
&
c
ans:d 3. A1,A2,A3 and A4 are activities called using intents.Then A1-A4-A2--A3.A4 calls A2 28 | P a g e
with intent flag FLAG_ACTIVITY_NO_HISTORY.When FLAG_ACTIVITY_NO_HISTORY.When finish method is called on A3, What will
be
currtent
running
the activity?
a)A1 b)A4 c)A3 d)A2 ans:
b
4. A1,A2,A3 and A4 are activities called using intents.Then A1-A2-A4--A3.A2 calls A4 with intent flag FLAG_ACTIVITY_CLEAR_TOP.When finish() method is called on A3, what will
be
current
running
the activity?
a)A4 b)A3 c)A2 d)A1 Ans:
a
5. A1,A2,A3 and A4 are activities called using intents.Then A1-A2-A3-A4. A3 calls A4 with no intent flag, when finish() method called on A4. What will be the current running activity? a)A2 b)A3 c)A4 d)A1 Ans: 6.
b The
29 | P a g e
plus(+)
means
in
statement
android:id="@+id/my_id"?
a) b) c)
Identify
it
Create XML
new parser
d)
as id
an and
should
add
parse
Both
id
and
resource
to
resources
exapnd
a
id
&
string b.
Ans:
b
7. When you want system to run the service indefinitely, by restarting it when get killed, use a)
START_NOT_STICKY
b)
START_REDELIVER_INTENT
c)
START_STICKY
d)
START_SERVICE_INDEFINITELY
Ans:
c
8)
Android
system
uses
intents
to
a)
broadcast
system
intents
b)
broadcast
custom
intents
c) d)
To
invoke All
other
applications of
from the
your
Ans:
9)
application. above. d
'Screen
has
turned
off'
is
an
example
a) b)
Normal Ordered
broadcast broadcast
c)
background
operation
d) Ans:
None a
10) If you try to acces the column which does not exit, system throws a) NullPointerException b) c) 30 | P a g e
illegalArgumentException ArrayIndexOutOfBoundsException
d)
SQLException
Ans: 11)
b Maximum
results
returned
by
getFromLocationName()
method
can
be
a) b)
2 3
c) d)
4 5
Ans:
d
12. The methods startForeground() and stopForeground() were introduced in which API
level.
a)
2.0
b)
3.0
C)
1.5
d)
2.2
Ans:
a
13. Should always first check availability of audio effects by calling the following method on the
corresponding
audio
effect
class.
a)
ischeckable()
b)
isavailable()
c) d) Ans:
isvaluable
() iscaview() a
14. Applications that require filtering based on screen size can use the attributes. a) 31 | P a g e
<supportmultiple-screens>
b)
<supports-screens>
c)
<supportall-screens
d)
supportevery-screen
Ans:
b
15. a) b)
what is
called calling
c)
if
you
d)
if
you
is
false
when another startService() don't want
with
component results
want to
respect
to
allow
wants to in a
allow binding
bind call
binding then
to with to
then
return
onBind() a
service onBind()
return Ibinder
Ans:
null object b
16)Android is licensed under which open source licensing license? | Android A.
Gnu's
GPL
B.
Apache/MIT
C.
OSS
D. Ans:
Sourceforge B
17)Although most people's first thought when they think of Android is Google, Android is not actually owned by Google. Who owns the Android platform? | Android A.
Oracle
B. C. D.
Technology
Open The
above
statement statement
Dalvik Alliance
Handset is
and
Android
is
owned
Ans:
by
Google C
18)As an Android programmer, what version of Android should you use as your minimum A. B. 32 | P a g e
development Versions Versions
target? 1.6 1.0
|
Android
or or
2.0 1.1
C.
Versions
1.2
or
1.3
D.
Versions
2.3
or
3.0
Ans:
A
19)What was Google's main business motivation for supporting Android? | Android A.
To
level
the
playing
field
for
mobile
devices
B. To directly compete with the iPhone C. To corner the mobile device application market for licensing purposes D.
To
allow
them
to
advertise
more
Ans:
D
20)What was the first phone released that ran the Android OS? | Android A.
B.
gPhone
T-Mobile
G1
C.
Motorola
Droid
D.
HTC
Hero
Ans:
B
21)From a phone manufacturer's point of view, what makes Android so great? | Android A. Aside from some specific drivers, it provides everything to make a phone work B.
It
makes
the
hardware
work
better
C. It allows them to compete with Apple's iPhone D. It allows users to create apps, generating revenue for the companies Ans:
A
22)What A.
It
is
a was
funny
fact orginaly
about
the
going
start to
of
Android? be
|
Android
called
UFO
B. The first version of Android was released without an actual phone on the market C. Androids main purpose was to unlock your car door when you left the keys inside of it. D. Was going to be a closed source application to make more money for its company. 33 | P a g e
Ans:
B
23)What
year
was
the
Open
Handset
Alliance
announced?
|
Android
A.
2005
B.
2006
C. D.
2007 2008
Ans:
C
24)A device with Android installed is needed to develop apps for Android. A.
True
B.
False
Ans:
B
25)Android tries hard to _____low-level components, such as the software stack, with interfaces
so
that
vendor-specific
code
can
be
managed
easily.
A.
confound
B. C.
absract modularize
D.
compound
Ans:
B
26)Google
licensed
some
proprietary
apps.
|
Android
A.
True
B.
False
Ans:
A
27)What
part
A. B. C.
of
the
Android
platform
low-level all
of
34 | P a g e
these
answers
#The
is
open
source?
|
Linux entire native
stack
is
an
Android modules
open
source
platform libraries
D.
application
E.
frame
work
complete
applications
Ans:
B
28)When
did
purchase
Android?
|
ANdroid
A.
2007
B. C.
2005 2008
D.
2010
Ans:
B
29)Android releases since 1.5 have been given nicknames derived how? | Android A.
Adjective
and
strange
animal
B. C.
Food Something
that
starts
D.
w/
'A'
->
Something
that
starts
w/
American
states
Ans:
30)Which
'B'...
B
one
is
not
a
nickname
of
a
version
of
Andriod?
|
Android
A.
cupcake
B. C.
Gingerbread Honeycomb
D.
Muffin
Ans:
D
31)Android doesn't make any assumptions about a device's screen size, resolution, or chipset.: A. B. Ans: 35 | P a g e
True False A
32)Which Android version had the greatest share of the market as of January 2011? | Android A.
1.1
B.
1.5
C.
2.3
D.
3.4
Ans:
B
33)Which piece of code used in Android is not open source? | Android A.
Keypad
driver
B.
WiFi?
driver
C. D.
Audio Power
driver management
Ans:
B
34)Android is built upon the Java Micro Edition (J2ME) version of Java. | Android A.
True
B.
False
Ans:
B
35)Which among these are NOT a part of Android's native libraries? | Android A.
Webkit
B. C.
Dalvik OpenGL
D.
SQLite
Ans:
36)Android
B
is
based
on
Linux
for
the
following
reason.
|
Android
A.
Security
B.
Portability
36 | P a g e
C.
Networking
D.
All
of
Ans:
these
D
37)What operating system is used as the base of the Android stack? | Android A. B.
Linux Windows
C.
Java
D.
XML
Ans:
A
38)What year was development on the Dalvik virtual machine started? | Android A.
2003
B.
2005
C.
2007
D.
2006
Ans:
B
39)What is a key difference with the distribution of apps for Android based devices than other
mobile
A.
Applications
device
platform
are
distributed
applications? by
Apple
| App
Android Store
only
B. Applications are distributed by multiple vendors with different policies on applications. C.
Applications are distributed distributed by multiple multiple vendors with the exact same policies policies on
applications. D.
Applications
Ans:
are
distributed
by
the
Android
Market
only.
B
40)When developing for the Android OS, Java byte code is compiled into what? | Android
37 | P a g e
A.
Java
B.
Dalvik
C.
source
code
application
code
Dalvik
D.
byte
C
code
source
Ans:
code
C
41)What
does
the
.apk
extension
A. B.
Application
C.
Android
stand
for?
|
Android
Application
D.
Program
Package Kit
Proprietary
Kit
Android
Ans:
Package
A
42)When you distribute your application commercially,you'll want to sign it with your own
key.
|
Android
A.
True
B.
False
Ans:
A
43)How does Google check for malicious software in the Android Market? | Android A.
Every
B.
Users
C. D.
new
Google A
Ans:
seperate
app report
is
scanned malicious
employees company
by
software
verify
monitors
the
a
virus
scanner
to
each
Android
Market
new
app
for
B
44)Which of these are not one of the three main components of the APK? | Android A.
Dalvik
B. C. D. Ans:
Executable Resources
Native
Libraries Webkit D
45)What is the name of the program that converts Java byte code into Dalvik byte code? |
38 | P a g e
Android
A.
Android
Interpretive
Compiler
(AIC)
B.
Dalvik
Converter
C.
Dex
compiler
D.
Mobile
Ans:
Interpretive
Compiler
(MIC)
C
46)Android
Applications
A. B.
must
be
After Before
signed.
they they
|
Android
are are
installed installed
C.
Never
D.
Within
two
weeks
Ans:
of
installation
B
47)Which of the following are not a component of an APK file? | Android A.
Resources
B.
All
of
these
are
components
C.
of
the
Native
D.
Libraries
Dalvik
Ans:
APK
executable
B
48)The AWT and Swing libraries have been removed from the Android library set. | Android A.
True
B.
False
Ans:
A
49)The R.java file is where you edit the resources for your project. | Android A.
True
B.
False
Ans: 50)What
B is
contained
A. B. 39 | P a g e
The The
within
the
manifest
permissions list
of
strings
xml
the used
file?
|
app in
Android
requires the
app
C.
The
D.
All
Ans:
code
other
choices
A
51)What A.
is
contained
Orientations
B. C.
and
The The
D.
The
within layouts
the that
Layout
specify
permissions strings
code
Ans:
which
is
xml
what
file?
the
required used
in
compiled
to
|
Android
display
by
looks
the the run
like. app. app.
the
app.
A
52)The
A.
source
emulated
device
for
android.
|
Android
Runs the same code base as the actual device, all the way down to the machine
layer. B.
Is more of a simulator, and and acts as a virtual machine for the the Android device.
C.
Runs the same code base as the actual device, however at a higher level.
D.
An imaginary machine built on the hopes and dreams of baby elephants.
Ans:
A
53)Your Java source code is what is directly run on the Android device. | ANdroid A.
True
B. Ans:
False B
54)The
Emulator
is
identical
emulating/simulating
to
running
a
real
what?
phone
EXCEPT
|
when
Android
A.
Telephony
B.
Applications
C.
Sensors
D. Ans:
The
55)How 40 | P a g e
is
emulator can
a
simulator
emulate/simulate all C different
from
aspects
an
of
a
emulator?
smart
|
phone.
Android
A.
Emulators are only used to play old SNES games, simulators are used for software
development B.
The emulator emulator is shipped with with the Android SDK and third party simulators are not
C.
The emulator can virtualize sensors and other hardware features, while the
simulator
cannot
D. The emulator imitates the machine executing the binary code, rather than simulating the behavior of the code at a higher level. Ans: 56)
D The
R
file
is
a(an)
generated
file
|
Android
A.
Automatically
B.
Manually
C.
Emulated
D. Ans: 57)An
None
activity
can
be
thought
A.
of
of
as
the
corresponding
A
to
above A
what?
Java
|
Android project
B.
A
Java
class
C. D.
A An
method object
call field
Ans:
B
58)To create an emulator, you need an AVD. What does it stand for? | Android A.
Android
Virtual
Display
B. C.
Android Active
Virtual Virtual
Device Device
D.
Application
Virtual
Display
Ans: 59)The
B Android
SDK
ships
with
A. B. Ans:
41 | P a g e
an
emulator.
|
Android True False
A
60)The ___________ file specifies the layout of your screen. | Android A.
Layout
file
B.
Manifest
file
C.
Strings
XML
D.
R
file
Ans:
A
61)The manifest explains what the application consists of and glues everything together. | Android A.
True
B.
False
Ans:
A
62)The Android Software Development Kit (SDK) is all you need to develop applications for Android. A.
True
B.
False
Ans:
A
63)What is the driving force behind an Android application and that ultimately gets converted into a Dalvik executable? | Android A.
Java
source
code.
B.
R-file.
C.
the
D. Ans:
emulator. the
A
SDK
64)While developing Android applications, developers can test their apps on... A.
Emulator
B. C. D. Ans: 65) How can
42 | P a g e
included
in
Physical Third-party All
Android Android
Emulators three
options
SDK phone
(Youwave, will
etc.) work.
D I check if an activity activity is already run running ning before starting it? it?
A.
NEW_TASK_LAUNCH
B.
FLAG_ACTIVITY_NEW_TASK in
C.
FLAG_ACTIVITY_SINGLE_TOP FLAG_ACTIVITY_SINGLE_TOP in
D.
B y
the
startActivity()
the the
method
call.
startActivity()
method
call.
startActivity()
method
call.
using <category android:name= android:name="android.intent.category.LAUNCHER" "android.intent.category.LAUNCHER" />
this category attribute. attribute.
43 | P a g e
in
