Android Basic Concept
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Transcript of Android Basic Concept
Slide 1
About Me
Md.Delwar HossainB.Sc in CSETrainer, Android Apps DeveloperExperience:Trainer at Open IT, Computer OperatorProfessional Course:BASIS,EATL,APPSO,Google Android Author: (Pending)Bookbd.com,
Contact Me
Gmail: [email protected]: 01673648918Skype: delwar.shuvoFacebook: Shuvo Delwar
Android
Android is a complete set of software for mobile devices such as tablet computers, notebooks, smartphones, electronic book readers, set-top boxes etc.It contains a linux-based Operating System, middleware and key mobile applications.
What is Android?Android is a software package and linux based operating system for mobile devices such as tablet computers and smartphones.It is developed by Google and later the OHA (Open Handset Alliance). Java language is mainly used to write the android code even though other languages can be used.
What is Open Handset Alliance (OHA)
It's a consortium of 84 companies such as google, samsung, AKM, synaptics, KDDI, Garmin, Teleca, Ebay, Intel etc.It was established on 5th November, 2007, led by Google. It is committed to advance open standards, provide services and deploy handsets using the Android Plateform.
Features of Android
1) It is open-source.2) Anyone can customize the Android Platform.3) There are a lot of mobile applications that can be chosen by the consumer.4) It provides many interesting features like weather details, opening screen, live RSS (Really Simple Syndication) feeds etc.5) It provides support for messaging services(SMS and MMS), web browser, storage (SQLite), connectivity (GSM, CDMA, Blue Tooth, Wi-Fi etc.), media, handset layout etc.
Categories of Android applicationsEntertainmentToolsCommunicationProductivityPersonalizationMusic and AudioSocialMedia and VideoTravel and Local etc.
Android Versions, Codename and API
Android Architecture
Android architecture or Android software stack is categorized into five parts:linux kernelnative libraries (middleware),Android RuntimeApplication FrameworkApplicationsLet's see the android architecture first.
Android Architecture
1) Linux kernel
It is the heart of android architecture that exists at the root of android architecture. Linux kernel is responsible for device drivers, power management, memory management, device management and resource access.
2) Native Libraries
On the top of linux kernel, their are Native libraries such as WebKit, OpenGL, FreeType, SQLite, Media, C runtime library (libc) etc.
The WebKit library is responsible for browser support, SQLite is for database, FreeType for font support, Media for playing and recording audio and video formats.
3) Android Runtime
In android runtime, there are core libraries and DVM (Dalvik Virtual Machine) which is responsible to run android application. DVM is like JVM but it is optimized for mobile devices. It consumes less memory and provides fast performance.
4) Android Framework
On the top of Native libraries and android runtime, there is android framework. Android framework includes Android API's such as UI (User Interface), telephony, resources, locations, Content Providers (data) and package managers. It provides a lot of classes and interfaces for android application development.
5) Applications
On the top of android framework, there are applications. All applications such as home, contact, settings, games, browsers are using android framework that uses android runtime and libraries. Android runtime and native libraries are using linux kernal.
Android Core Building Blocks
The core building blocks or fundamental components of android are activities, views, intents, services, content providers, fragments and AndroidManifest.xml.
Android Core Building Blocks
ActivityAn activity is a class that represents a single screen. It is like a Frame in AWT.ViewA view is the UI element such as button, label, text field etc. Anything that you see is a view.
Android Core Building Blocks
IntentIntent is used to invoke components. It is mainly used to:Start the serviceLaunch an activityDisplay a web pageDisplay a list of contactsBroadcast a messageDial a phone call etc.
Android Core Building Blocks
ServiceService is a background process that can run for a long time. There are two types of services local and remote. Local service is accessed from within the application whereas remote service is accessed remotely from other applications running on the same device.Content ProviderContent Providers are used to share data between the applications.
Android Core Building Blocks
FragmentFragments are like parts of activity. An activity can display one or more fragments on the screen at the same time.AndroidManifest.xmlIt contains information's about activities, content providers, permissions etc. It is like the web.xml file in Java EE.Android Virtual Device (AVD)It is used to test the android application without the need for mobile or tablet etc. It can be created in different configurations to emulate different types of real devices.
Install Android
Android supports java, c++, c# etc. language to develop android applications. Java is the officially supported language for android. All the android examples of this site is developed using Java language and Eclipse IDE.
Install Android
Install the JDKDownload and Install the android SDKDownload Android Studiohttp://developer.android.com/index.htmlCreate the AVD Create the hello android application
AndroidManifest.xml file in android
It performs some other tasks also:It is responsible to protect the application to access any protected parts by providing the permissions. It also declares the android api that the application is going to use.It lists the instrumentation classes. The instrumentation classes provides profiling and other information's. These information's are removed just before the application is published etc.This is the required xml file for all the android application and located inside the root directory.
Android Hide Title Bar Example
The requestWindowFeature(Window.FEATURE_NO_TITLE) method of Activity must be called to hide the title. But, it must be coded before the setContentView method.The setFlags() method of Window class is used to display content in full screen mode. You need to pass the WindowManager.LayoutParams.FLAG_FULLSCREEN constant in the setFlags method.
Android Hide Title Bar Example
Android Screen Orientation
The screenOrientation is the attribute of activity element. The orientation of android activity can be portrait, landscape, sensor, unspecified etc. You need to define it in the AndroidManifest.xml file. For example:
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