3) What is the Android Architecture?
Android Architecture is made up of 4 key components:
The Android Framework is an important aspect of the Android Architecture. Here you can find all the classes and methods that developers would need in order to write applications on the Android environment.
AAPT is short for Android Asset Packaging Tool. This tool provides developers with the ability to deal with zip-compatible archives, which includes creating, extracting as well as viewing its contents.
47) What is portable wi-fi hotspot?
Portable Wi-Fi Hotspot allows you to share your mobile internet connection to other wireless device. For example, using your Android-powered phone as a Wi-Fi Hotspot, you can use your laptop to connect to the Internet using that access point.
In Android development, an action is what the intent sender wants to do or expected to get as a response. Most application functionality is based on the intended action.
Q What is an Activity? Which method is implemented by all subclasses of an Activity?
An Activity is the screen representation of an application in Android.
It serves as an entry point for the user’s interaction. Each activity has a layout file where you can place your UI. An application can have different activities. For example, facebook start page where you enter your email/phone and password to login acts as an activity.
Below are the two methods which almost all subclasses of Activity will implement:
An activity is implemented as a subclass of Activity class as follows:
Q3. What are the features of Android?
Google has changed the lives of everyone by launching a product that improves the mobile experience for everyone. Android helps in understanding your tastes and needs, by giving various features such as having wallpapers, themes, and launchers which completely change the look of your device’s interface.
Android has plenty of features. Some of the features are listed below:
Q3 What is the difference between Service and Thread?
| Service | Thread |
| Service is like an Activity but has no interface. | A Thread is a concurrent unit of execution. |
| A Service is not a separate process. It works in background until the service or someone else explicitly stop it. | By default, all components of the same application run in the same process and thread (called the “main” thread). |
| Service is not killed when an application is killed. | Thread is killed when an Application is killed. |
| It expose some of its functionality to other applications by calling Context.bindService(). | GOOGLE has brought in Handlers and loopers into android threads. |
43) What are the core components under the Android application architecture?
There are 5 key components under the Android application architecture:
– services – intent – resource externalization – notifications – content providers
7) What is the use of an activityCreator?
An activityCreator is the first step towards the creation of a new Android project. It is made up of a shell script that will be used to create new file system structure necessary for writing codes within the Android IDE.
Activities are what you refer to as the window to a user interface. Just as you create windows in order to display output or to ask for an input in the form of dialog boxes, activities play the same role, though it may not always be in the form of a user interface.
Intents displays notification messages to the user from within the Android enabled device. It can be used to alert the user of a particular state that occurred. Users can be made to respond to intents.
Activities can be closed, or terminated anytime the user wishes. On the other hand, services are designed to run behind the scenes, and can act independently. Most services run continuously, regardless of whether there are certain or no activities being executed.