Download www.android.com Simone Livraghi Solution Architect simone

www.android.com
Simone Livraghi
Solution Architect
[email protected]
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Summary
What is Android?
Dalvik
Application Fundamentals
Application Components
Market
Links
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What is Android?
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What is Android?
The Android SDK provides the tools and APIs necessary to begin
developing applications on the Android platform using the Java
programming language.
Android is a software stack for mobile devices that includes an operating system, middleware and key applications
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What is Android?
Features
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Application framework
Dalvik virtual machine
Integrated browser
Optimized graphics
– hardware acceleration optional
SQLite
Media support
GSM Telephony
– hardware dependent
Bluetooth, EDGE, 3G, and WiFi hardware dependent
Camera, GPS, compass, and accelerometer hardware dependent
Rich development environment
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What is Android?
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What is Android?
System C library - BSD based
Media Libraries - MPEG4, H.264, MP3, AAC, AMR, JPG, and
PNG
Surface Manager
LibWebCore
SGL - 3D Scene Graph Library
3D libraries - OpenGL ES 1.0 APIs
FreeType
SQLite
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What is Android?
Android relies on Linux version 2.6 for core system services such
as security, memory management, process management, network
stack, and driver model. The kernel also acts as an abstraction
layer between the hardware and the rest of the software stack.
http://android.git.kernel.org
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Application Fundamentals
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Application Fundamentals
Android applications are written in the Java programming language.
Each Android application lives in its own security sandbox:
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Android is a multi-user system in which each application is a
different user.
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Each application a unique Linux user ID
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Each process has its own virtual machine
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application's code runs in isolation from other ones
Every application runs in its own Linux process
Android starts the process when any of the application's components need to be executed
Android shuts down the process when it's no longer needed
Android shuts down the process when the system must recover
memory
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Dalvik
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Dalvik
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Dalvik - Memory
The Dalvik virtual machine is a register-based virtual machine. It is
optimized for low memory requirements, and is designed to allow
multiple VM instances to run at once, relying on the underlying operating system for process isolation, memory management and
threading support.
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Total system RAM: 64 MB.
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Available RAM after low-level startup: 40 MB.
Available RAM after high-level services have started: 20 MB.
Multiple independent mutually-suspicious processes
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Separate address spaces.
Separate memory.
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Dalvik – DEX
Dalvik is often referred to as a Java Virtual Machine, but this is not
strictly accurate, as the bytecode on which it operates is not Java
bytecode.
Instead, a tool named dx, included in the Android SDK, transforms
the Java Class files of Java classes compiled by a regular Java
compiler into another class file format (the .dex format).
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Dalvik – DEX
header
string_ids
type_ids
ids
proto_ids
class_defs
data
field_ids
method_ids
“Hello World!!!”
"Lcom/google/Blort;"
...
int
String
Com.google.Blort
...
void fn(int)
double fn(Object, int)
String fn()
...
String.offset
Integer.MAX_VALUE
...
PrintStream.println(…)
Collection.size()
...
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Dalvik – DEX
.jar
.class
heterogeneous
constant pool
data
.dex
header
ids
.class
heterogeneous
constant pool
data
...
class_defs
data
...
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Dalvik – DEX example
public interface Zapper {
}
public String zap(String s, Object o);
public class Blort implements Zapper {
}
public String zap(String s, Object o) {
...;
}
public class ZapUser {
}
public void useZap(Zapper z) {
z.zap(...);
}
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Dalvik – DEX example (.jar)
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Dalvik – DEX example (.dex)
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Dalvik - DEX
common system libraries
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web browser app
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(U) 21445320 — 100%
(J) 10662048 — 50%
(D) 10311972 — 48%
(U) 470312 — 100%
(J) 232065 — 49%
(D) 209248 — 44%
alarm clock app
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(U) 119200 — 100%
(J) 61658 — 52%
(D) 53020 — 44%
(U) uncompressed jar file
(J) compressed jar file
(D) uncompressed dex file
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Dalvik - Memory
Dalvik manages four Kinds Of Memory
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clean vs. dirty
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clean: mmap()ed and unwritten
cirty: malloc()ed
shared vs. private
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shared: used by many processes
private: used by only one process
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Dalvik - Memory
Dalvik manages four Kinds Of Memory
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clean (shared or private)
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shared dirty
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common dex files (libraries)
application-specific dex files
library “live” dex structures
shared copy-on-write heap (mostly not written)
private dirty
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application “live” dex structures
application heap
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Dalvik – Garbage collector
Separate process, separate heaps, separate Gcs.
GCs must be independent.
GC should respect the sharing.
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Dalvik - CPU
The CPU efficiency problem
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CPU speed: 250-500MHz
Bus speed: 100MHz
Data cache: 16-32K
Available RAM for apps: 20 MB
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Dalvik - CPU
No JIT
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usually doesn’t matter
lots of native code
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system provides libs for graphics, media
JNI available
hardware support common (graphics, audio)
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Dalvik - CPU
Install-Time Work
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Verification
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dex structures aren’t “lying”
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valid indices
valid offsets
code can’t misbehave
Optimization
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byte-swapping and padding (unnecessary on ARM)
static linking
“inlining” special native methods
pruning empty methods
adding auxiliary data
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Application Components
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Application Components
The Android Manifest
Activity
Service
Content provider
Broadcast receiver
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The Android Manifest
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The Android Manifest
Before the Android system can start an application component, the
system must know that the component exists by reading the application's AndroidManifest.xml file.
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Identify any user permissions the application requires
Declare the minimum API Level required by the application
Declare hardware and software features used or required by the
application
API libraries the application needs to be linked against
Declaring components
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<activity>, <service>, <receiver>, <provider>
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The Android Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.helloworld"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="14" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:label="@string/app_name"
android:name=".ExampleActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
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Activity
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Activity
An Activity is an application component that provides a screen with
which users can interact in order to do something.
An application usually consists of multiple activities that are loosely bound to each other.
An Activity should be declared in the manifest file in order for it to
be accessible to the system.
<activity
android:label="@string/app_name"
android:name=".ExampleActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
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Activity - Lifecycle
When an activity transitions into
and out of the different states
described above, it is notified
through various callback methods.
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OnCreate
OnStart
OnResume
OnPause
OnStop
OnRestart
OnDestroy
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Activity - Lifecycle
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Activity - Lifecycle
You can start another activity by calling startActivity(), passing it
an Intent that describes the activity you want to start.
Intent intent = new Intent(this, SecondActivity.class);
startActivity(intent);
You can shut down an activity by calling its finish() method. You
can also shut down a separate activity that you previously started
by calling finishActivity().
finishActivity(ACTIVITY_CODE);
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Activity - Lifecycle
Sometimes, you might want to receive a result from the activity
that you start.
private void pickContact() {
Intent intent = new Intent(Intent.ACTION_PICK, Contacts.CONTENT_URI);
startActivityForResult(intent, PICK_CONTACT_REQUEST);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == Activity.RESULT_OK &&
requestCode == PICK_CONTACT_REQUEST) {
}
}
Cursor cursor = getContentResolver().query(data.getData(),
new String[] {Contacts.DISPLAY_NAME}, null, null, null);
if (cursor.moveToFirst()) {
int columnIndex = cursor.getColumnIndex(Contacts.DISPLAY_NAME);
String name = cursor.getString(columnIndex);
}
Activity - Intent
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An intent is an abstract description of an operation to be performed.
An Intent object can contain:
● Component name
Example: Activity Class
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Action
ACTION_EDIT, ACTION_VIEW, ACTION_PICK, etc.
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Data
Category
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CATEGORY_HOME, CATEGORY_LAUNCHER,
CATEGORY_PREFERENCE, etc.
Extras
Flags
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Activity - Intent
Intents can be divided into two groups:
● Explicit intents
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designate the target component by its name
Intent intent = new Intent(this, SecondActivity.class);
startActivity(intent);
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Implicit intents
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do not name a target
Intent intent = new Intent(Intent.ACTION_SEND);
intent.putExtra(Intent.EXTRA_EMAIL, recipientArray);
startActivity(intent);
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Activity - Intent
To inform the system which implicit intents they can handle, activities, services, and broadcast receivers can have one or more intent filters.
<activity android:name=".ExampleActivity"
android:label="@string/app_name" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".SecondActivity" >
<intent-filter >
<action android:name="android.intent.action.VIEW" />
<action android:name="android.intent.action.EDIT" />
<action android:name="android.intent.action.PICK" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="vnd.android.cursor.dir/vnd.example.mail" />
</intent-filter>
<intent-filter >
<action android:name="android.intent.action.SEND" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="vnd.android.cursor.item/vnd.example.mail" />
</intent-filter>
</activity>
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Activity - UI
The user interface for an activity is provided by a hierarchy of
views.
The most common way to define a layout using views is with an
XML layout file saved in your application resources.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/myTextView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
android:textSize="38dp"
/>
</LinearLayout>
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Activity - UI
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Activity - UI
You can set the layout as the UI for your activity with
setContentView(), passing the resource ID for the layout.
public class ExampleActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
public final class R {
public static final class attr {
}
public static final class drawable {
public static final int ic_launcher=0x7f020000;
}
public static final class id {
public static final int myTextView=0x7f050000;
}
public static final class layout {
public static final int main=0x7f030000;
}
public static final class string {
public static final int app_name=0x7f040001;
public static final int hello=0x7f040000;
}
}
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Activity - Fragment
A Fragment represents a behavior or a portion of user interface in
an Activity.
You can combine multiple fragments in a single activity to build a
multi-pane UI and reuse a fragment in multiple activities.
Android introduced fragments in Android 3.0 (API level 11), primarily to support more dynamic and flexible UI designs on large
screens, such as tablets.
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Activity - Fragment
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Activity - Fragment
The application can embed two fragments in Activity A, when running on a tablet-sized device.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment android:name="com.example.news.ArticleListFragment"
android:id="@+id/list"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
<fragment android:name="com.example.news.ArticleReaderFragment"
android:id="@+id/viewer"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
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Activity - Fragment
On a handset-sized screen, Activity A includes only the fragment
for the list of articles, and when the user selects an article, it starts
Activity B, which includes the second fragment to read the article.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout ...>
<fragment android:name="com.example.news.ArticleListFragment"
android:id="@+id/list"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout ...>
<fragment android:name="com.example.news.ArticleReaderFragment"
android:id="@+id/viewer"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>
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Activity – Fragment lifecycle
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Activity – Fragment lifecycle
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Activity - Supporting Multiple Screens
Terms and concepts
● Screen size
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Actual physical size, measured as the screen's diagonal.
small, normal, large, and extra large
Screen density
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The quantity of pixels within a physical area of the screen; usually
referred to as dpi (dots per inch).
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Orientation
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The orientation of the screen from the user's point of view.
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landscape or portrait
Resolution
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low, medium, high, and extra high
The total number of physical pixels on a screen.
Density-independent pixel (dp)
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A virtual pixel unit that you should use when defining UI layout, to
express layout dimensions or position in a density-independent way.
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px = dp * (dpi / 160)
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Activity - Supporting Multiple Screens
Basic Guidelines
● Explicitly declare in the manifest which screen sizes your application supports
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you should include the <supports-screens> element in your manifest file
Provide different layouts for different screen sizes
res/layout/my_layout.xml
res/layout-small/my_layout.xml
res/layout-large/my_layout.xml
res/layout-xlarge/my_layout.xml
res/layout-xlarge-land/my_layout.xml
●
Provide different bitmap drawables for different screen densities
res/drawable-mdpi/my_icon.png
res/drawable-hdpi/my_icon.png
res/drawable-xhdpi/my_icon.png
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Activity - Supporting Multiple Screens
Basic Guidelines
● Build your activity designs based on fragments
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Use the action bar
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You can think of a fragment as a modular section of an activity
Ensure your design is flexible enough for the system to adjust the
action bar layout
Implement flexible layouts
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A flexible layout design allows your application to adapt to variations in screen sizes.
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Activity – Action Bar
The Action Bar is an important UI component for Android apps on
both tablets and handsets.
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Service
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Service
A Service is an application component that can perform long-running operations in the background and does not provide a user interface.
Another application component can start a service and it will continue to run in the background even if the user switches to another
application.
Like activities (and other components), you must declare all services in your application's manifest file.
<manifest ... >
...
<application ... >
<service android:name=".ExampleService" />
...
</application>
</manifest>
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Service
A service can essentially take two forms:
● Started
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A service is "started" when an application component (such as an
activity) starts it by calling startService().
Once started, a service can run in the background indefinitely,
even if the component that started it is destroyed.
Bound
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A service is "bound" when an application component binds to it by
calling bindService().
A bound service offers a client-server interface that allows components to interact with the service.
A bound service runs only as long as another application component is bound to it.
Multiple components can bind to the service at once.
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Service
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Service - AIDL
AIDL (Android Interface Definition Language) allows you to define
the programming interface that both the client and service agree
upon in order to communicate with each other using interprocess
communication (IPC).
On Android, one process cannot normally access the memory of
another process. So to talk, they need to decompose their objects
into primitives that the operating system can understand, and marshall the objects across that boundary for you.
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Service - AIDL
You must define your AIDL interface in an .aidl file using the Java
programming language syntax.
interface IHelloService {
Bundle sendRequest(in Bundle request);
}
If you have a class that you would like to send from one process to
another through an IPC interface, you can do that.
You must ensure that the code for your class is available to the
other side of the IPC channel and your class must support the
Parcelable interface.
Parcel is not a general-purpose serialization mechanism. It is designed as a high-performance IPC transport.
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Service - AIDL - Marshalling
Marshalling (computer science)
From Wikipedia, the free encyclopedia
In computer science, marshalling (sometimes spelled marshaling,
similar to serialization) is the process of transforming the memory
representation of an object to a data format suitable for storage or
transmission. It is typically used when data must be moved between different parts of a computer program or from one program
to another.
Marshalling is a process that is used to communicate to remote
objects with an object (in this case a serialized object). It simplifies
complex communication, using custom/complex objects to communicate - instead of primitives.
The opposite, or reverse, of marshalling is called unmarshalling (or
demarshalling, similar to deserialization).
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Service - AIDL
Include the .aidl file in the project src/ directory.
Declare an instance of the IBinder interface (generated based
on the AIDL).
Implement ServiceConnection.
Call Context.bindService(), passing in your ServiceConnection
implementation.
In your implementation of onServiceConnected(), you will receive an IBinder instance (called service). Call YourInterfaceName.Stub.asInterface((IBinder)service) to cast the returned parameter to YourInterface type.
Call the methods that you defined on your interface. You should
always trap DeadObjectException exceptions, which are thrown
when the connection has broken; this will be the only exception
thrown by remote methods.
To disconnect, call Context.unbindService() with the instance of
your interface.
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Content Providers
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Content Providers
Content providers store and retrieve data and make it accessible
to all applications.
–
The application's data are stored using the system SQLite library.
They're the only way to share data across applications; there's no
common storage area that all Android packages can access.
–
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The application's data are stored into the sandbox.
Only the Content Provider could be shared.
Each content provider exposes a public URI that uniquely identifies its data set.
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Content Providers
To let the Android system know about the content provider you've
developed, declare it with a <provider> element in the application's
AndroidManifest.xml file.
<provider android:name=".TransportationProvider"
android:authorities="com.example.transportationprovider"
... />
</provider>
Android ships with a number of content providers for common data
types
–
audio, video, images, personal contact information, etc.
65
Content Providers
All content providers implement a common interface for querying
the provider and returning results — as well as for adding, altering,
and deleting data.
It's an interface that clients use indirectly, most generally through
ContentResolver objects.
–
You get a ContentResolver by calling getContentResolver()
Content providers expose their data as a simple table on a database model.
–
Every record includes a numeric _ID field that uniquely identifies
the record within the table.
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Content Providers - ContentResolver
public boolean onCreate()
public final String getType (Uri url)
public final Cursor query ( Uri uri, String[] projection,
String selection, String[] selectionArgs, String sortOrder )
public final Uri insert (Uri url, ContentValues values)
public final int update (Uri uri, ContentValues values,
String where, String[] selectionArgs)
public final int delete (Uri url, String where,
String[] selectionArgs)
67
Content Providers - URI
68
Content Providers - Query
_ID
NUMBER
NUMBER_KEY LABEL
NAME
TYPE
13
(425) 555 6677
425 555 6677
Kirkland office
Bully
Pulpit
TYPE_WORK
44
(212) 555-1234 212 555 1234
NY apartment
Alan Vain
TYPE_HOME
45
(212) 555-6657 212 555 6657
Downtown
office
Alan Vain
TYPE_MOBILE
53
201.555.4433
Love Nest
Rex Cars
TYPE_HOME
201 555 4433
String[] projection = new String[] {
People._ID, People._COUNT,
People.NAME,People.NUMBER };
Cursor cursor = getContentResolver().query(
People.CONTENT_URI,
projection,
null,
// Selection
null,
// Selection arguments
People.NAME + " ASC");
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Content Providers - Query
_ID
_COUNT
NUMBER
NAME
44
3
(212) 5551234
Alan Vain
13
3
(425) 555
6677
Bully
Pulpit
53
3
201.555.4433
Rex Cars
String[] projection = new String[] {
People._ID, People._COUNT,
People.NAME,People.NUMBER };
Cursor cursor = getContentResolver().query(
People.CONTENT_URI,
projection,
null,
// Selection
null,
// Selection arguments
People.NAME + " ASC");
70
Content Providers - Insert
_ID
NUMBER
NUMBER_KEY LABEL
NAME
TYPE
13
(425) 555 6677
425 555 6677
Kirkland office
Bully
Pulpit
TYPE_WORK
44
(212) 555-1234 212 555 1234
NY apartment
Alan Vain
TYPE_HOME
45
(212) 555-6657 212 555 6657
Downtown
office
Alan Vain
TYPE_MOBILE
53
201.555.4433
Love Nest
Rex Cars
TYPE_HOME
201 555 4433
ContentValues contentValues = new ContentValues();
contentValues.put(People.NAME, "Simone Livraghi");
contentValues.put(People.LABEL, "Io sono L");
contentValues.put(People.TYPE, People.TYPE_MOBILE);
contentValues.put(People.NUMBER, "(333) 3333333");
getContentResolver().insert(People.CONTENT_URI, contentValues);
71
Content Providers - Insert
_ID
NUMBER
NUMBER_KEY LABEL
NAME
TYPE
13
(425) 555 6677
425 555 6677
Kirkland office
Bully
Pulpit
TYPE_WORK
44
(212) 555-1234 212 555 1234
NY apartment
Alan Vain
TYPE_HOME
45
(212) 555-6657 212 555 6657
Downtown
office
Alan Vain
TYPE_MOBILE
53
201.555.4433
201 555 4433
Love Nest
Rex Cars
TYPE_HOME
54
(333) 3333333
333 333 3333
Io sono L
Simone
Livraghi
TYPE_MOBILE
ContentValues contentValues = new ContentValues();
contentValues.put(People.NAME, "Simone Livraghi");
contentValues.put(People.LABEL, "Io sono L");
contentValues.put(People.TYPE, People.TYPE_MOBILE);
contentValues.put(People.NUMBER, "(333) 3333333");
getContentResolver().insert(People.CONTENT_URI, contentValues);
72
Content Providers - Update
_ID
NUMBER
NUMBER_KEY LABEL
NAME
TYPE
13
(425) 555 6677
425 555 6677
Kirkland office
Bully
Pulpit
TYPE_WORK
44
(212) 555-1234 212 555 1234
NY apartment
Alan Vain
TYPE_HOME
45
(212) 555-6657 212 555 6657
Downtown
office
Alan Vain
TYPE_MOBILE
53
201.555.4433
201 555 4433
Love Nest
Rex Cars
TYPE_HOME
54
(333) 3333333
333 333 3333
Io sono L
Simone
Livraghi
TYPE_MOBILE
ContentValues contentValues = new ContentValues();
contentValues.put(People.NAME, "Alan Vaini");
String selection = People.NAME + "='Alan Vain'";
getContentResolver().update(
People.CONTENT_URI,
null,
// Projection
selection,
null,
// Selection arguments
People.NAME + " ASC");
73
Content Providers - Update
_ID
NUMBER
NUMBER_KEY LABEL
NAME
TYPE
13
(425) 555 6677
425 555 6677
Kirkland office
Bully
Pulpit
TYPE_WORK
44
(212) 555-1234 212 555 1234
NY apartment
Alan Vaini TYPE_HOME
45
(212) 555-6657 212 555 6657
Downtown
office
Alan Vaini TYPE_MOBILE
53
201.555.4433
201 555 4433
Love Nest
Rex Cars
TYPE_HOME
54
(333) 3333333
333 333 3333
Io sono L
Simone
Livraghi
TYPE_MOBILE
ContentValues contentValues = new ContentValues();
contentValues.put(People.NAME, "Alan Vaini");
String selection = People.NAME + "='Alan Vain'";
getContentResolver().update(
People.CONTENT_URI,
null,
// Projection
selection,
null,
// Selection arguments
People.NAME + " ASC");
74
Content Providers - Delete
_ID
NUMBER
NUMBER_KEY LABEL
NAME
TYPE
13
(425) 555 6677
425 555 6677
Kirkland office
Bully
Pulpit
TYPE_WORK
44
(212) 555-1234 212 555 1234
NY apartment
Alan Vaini TYPE_HOME
45
(212) 555-6657 212 555 6657
Downtown
office
Alan Vaini TYPE_MOBILE
53
201.555.4433
201 555 4433
Love Nest
Rex Cars
TYPE_HOME
54
(333) 3333333
333 333 3333
Io sono L
Simone
Livraghi
TYPE_MOBILE
String selection = People._ID "=" + 44;
getContentResolver().delete(
People.CONTENT_URI,
selection,
null);
// Selection arguments
75
Content Providers - Delete
_ID
NUMBER
NUMBER_KEY LABEL
NAME
TYPE
13
(425) 555 6677
425 555 6677
Kirkland office
Bully
Pulpit
TYPE_WORK
45
(212) 555-6657 212 555 6657
Downtown
office
Alan Vaini TYPE_MOBILE
53
201.555.4433
201 555 4433
Love Nest
Rex Cars
TYPE_HOME
54
(333) 3333333
333 333 3333
Io sono L
Simone
Livraghi
TYPE_MOBILE
String selection = People._ID "=" + 44;
getContentResolver().delete(
People.CONTENT_URI,
selection,
null);
// Selection arguments
76
Broadcast Receiver
77
Broadcast Receiver
To let the Android system know about the broadcast receiver
you've developed, declare it with a <receiver> element in the application's AndroidManifest.xml file.
<receiver android:enabled="true" android:name=".NetworkReceiver">
<intent-filter>
<action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
</intent-filter>
</receiver>
78
Broadcast Receiver - Lifecycle
A BroadcastReceiver object is only valid for the duration of the call
to onReceive(Context, Intent).
public class NetworkReceiver extends BroadcastReceiver {
}
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
}
79
Market
http://market.android.com
80
Links
http://www.android.com
http://developer.android.com
www.android.com
Simone Livraghi
Solution Architect
[email protected]