Android Interview Questions And Answers
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Android is a stack of software for mobile devices which includes an Operating System, middleware and some key applications. |
A single screen in an application, with supporting Java code. |
A class (Intent) which describes what a caller desires to do. The caller will send this intent to Android\'s intent resolver, which finds the most suitable activity for the intent. E.g. opening a PDF document is an intent, and the Adobe Reader apps will be the perfect activity for that intent (class). |
sendStickyBroadcast() performs a sendBroadcast(Intent) known as sticky, i.e. the Intent you are sending stays around after the broadcast is complete, so that others can quickly retrieve that data through the return value of registerReceiver(BroadcastReceiver, |
How the nine-patch Image different from a regular bitmap? Alternatively, what is the difference between nine-patch Image vs regular Bitmap Image? |
A user defined JSON, XML, bitmap, or other file, injected into the application build process, which can later be loaded from code. |
How will you record a phone call in Android? or How to handle an Audio Stream for a call in Android? |
Permission.PROCESS_OUTGOING_CALLS: Will Allow an application to monitor, modify, or abort outgoing calls. So using that permission we can monitor the Phone calls. |
Yes. |
Yes |
The APK file is compressed AndroidManifest.xml file with extension .apk. It also includes the application code (.dex files), resource files, and other files which are compressed into a single .apk file. |
The Google translator translates the data of one language into another language by using XMPP to transmit data. You can type the message in English and select the language which is understood by the citizens of the country in order to reach the message to the citizens. |
Android Application Architecture has the following components: Services like Network Operation Intent - To perform inter-communication between activities or services Resource Externalization - such as strings and graphics Notification signaling users - light, sound, icon, notification, dialog etc. Content Providers - They share data between applications |
What dialog boxes are supported in android?Android supports 4 dialog boxes: |
AlertDialog: An alert dialog box supports 0 to 3 buttons and a list of selectable elements, including check boxes and radio buttons. Among the other dialog boxes, the most suggested dialog box is the alert dialog box. ProgressDialog: This dialog box displays a progress wheel or a progress bar. It is an extension of AlertDialog and supports adding buttons. DatePickerDialog: This dialog box is used for selecting a date by the user. TimePickerDialog: This dialog box is used for selecting time by the user. |
Components can be reused and replaced by the application framework. Optimized DVM for mobile devices SQLite enables to store the data in a structured manner. Supports GSM telephone and Bluetooth, WiFi, 3G and EDGE technologies The development is a combination of a device emulator, debugging tools, memory profiling and plug-in for Eclipse IDE. |
TTL is a value in data packet of Internet Protocol. It communicates to the network router whether or not the packet should be in the network for too long or discarded. Usually, data packets might not be transmitted to their intended destination within a stipulated period of time. The TTL value is set by a system default value which is an 8-bit binary digit field in the header of the packet. The purpose of TTL is, it would specify certain time limit in seconds, for transmitting the packet header. When the time is exhausted, the packet would be discarded. Each router receives the subtracts count, when the packet is discarded, and when it becomes zero, the router detects the discarded packets and sends a message, Internet Control Message Protocol message back to the originating host. |
It is a resizable bitmap resource that can be used for backgrounds or other images on the device. The NinePatch class permits drawing a bitmap in nine sections. The four corners are unscaled; the four edges are scaled in one axis, and the middle is scaled in both axes. |
The following are the exceptions that are supported by Android InflateException : When an error conditions are occurred, this exception is thrown Surface.OutOfResourceException: When a surface is not created or resized, this exception is thrown SurfaceHolder.BadSurfaceTypeException: This exception is thrown from the lockCanvas() method, when invoked on a Surface whose is SURFACE_TYPE_PUSH_BUFFERS WindowManager.BadTokenException: This exception is thrown at the time of trying to add view an invalid WindowManager.LayoutParamstoken. |
IP datagram can be used to describe a portion of IP data. Each IP datagram has set of fields arranged in an order. The order is specific which helps to decode and read the stream easily. IP datagram has fields like Version, header length, Type of service, Total length, checksum, flag, protocol, Time to live, Identification, source and destination ip address, padding, options and payload. MTU:- Maximum Transmission Unit is the size of the largest packet that a communication protocol can pass. The size can be fixed by some standard or decided at the time of connection Fragmentation is a process of breaking the IP packets into smaller pieces. Fragmentation is needed when the datagram is larger than the MTU. Each fragment becomes a datagram in itself and transmitted independently from source. When received by destination they are reassembled. |
sendStickyBroadcast() performs a sendBroadcast(Intent) known as sticky, i.e. the Intent you are sending stays around after the broadcast is complete, so that others can quickly retrieve that data through the return value of registerReceiver(BroadcastReceiver, IntentFilter). In all other ways, this behaves the same as sendBroadcast(Intent). One example of a sticky broadcast sent via the operating system is ACTION_BATTERY_CHANGED. When you call registerReceiver() for that action -- even with a null BroadcastReceiver -- you get the Intent that was last broadcast for that action. Hence, you can use this to find the state of the battery without necessarily registering for all future state changes in the battery. |
Android Debug Bridge, a command-line debugging application shipped with the SDK. It provides tools to browse the device, copy tools on the device, and forward ports for debugging. |
It is a resizable bitmap resource that can be used for backgrounds or other images on the device. The NinePatch class permits drawing a bitmap in nine sections. The four corners are unscaled; the four edges are scaled in one axis, and the middle is scaled in both axes. |
magine a situation that you are in a country where no one understands the language you speak and you can not read or write. However, you have mobile phone with you. With a mobile phone with android, the Google translator translates the data of one language into another language by using XMPP to transmit data. You can type the message in English and select the language which is understood by the citizens of the country in order to reach the message to the citizens. |
No, Android is not yet available in a ROM format. Currently Android is installed by using a clean SD Card, and booted from there. It is booted by running a special application called 'Haret.exe' residing on your SD Card which will terminate the Windows kernel and boot into Linux/Android. It can't easily be run from ROM because a) it's too experimental to risk putting in ROM and then killing a device and b) WinMo does some hardware initialisation that isn't documented, but is needed before Android can run. |
Future of the mobile application development is bright |
I have used up all the space on one of my homescreens and I want to add some more widgets to a new homescreen. I can't figure out how to add a new homescreen |
Generally, it's very difficult to detail them, unless there is a significant new feature (in which case, that will be very well advertised!). Usually it's minor speed improvements, bug fixes etc... and sometimes, new bugs are introduced (so bear that in mind) |
Android Application Architecture has the following components: Services ? like Network Operation Intent - To perform inter-communication between activities or services Resource Externalization - such as strings and graphics Notification signaling users - light, sound, icon, notification, dialog etc. Content Providers - They share data between applications |
The name of Android?s virtual machine. The Dalvik VM is an interpreter-only virtual machine that executes files in the Dalvik Executable (.dex) format, a format that is optimized for efficient storage and memory-mappable execution. The virtual machine is register-based, and it can run classes compiled by a Java language compiler that have been transformed into its native format using the included ?dx? tool. The VM runs on top of Posix-compliant operating systems, which it relies on for underlying functionality (such as threading and low level memory management). The Dalvik core class library is intended to provide a familiar development base for those used to programming with Java Standard Edition, but it is geared specifically to the needs of a small mobile device. |
Yes |
The OHA members have endeavoured to develop Android, the open source mobile platform consisting of an OS, web browser and key applications. Different companies have different contributions to make and roles to play. For instance, the software companies like Google are developing the requisite software, the hardware companies the chipsets and the mobile companies are ensuring compatible handsets for Android. |
In Android in Stable for Android package file,In this Package file containing all of the files to related for a single Android application.In this file itself is a compressed collection of an AndroidManifest.xml file. it's application code is ".dex files",resource files and other files.it's file is compiled into a single .apk file. |