- Why do we pass context in Android?
- What are the different kinds of context in Android?
- What is getBaseContext in Android?
- What is singleton class in Android?
- What is Android ViewGroup?
- What is Android ContextWrapper?
- What is attachBaseContext?
- What is the difference between getApplicationContext and getBaseContext in Android?
- Which database is used in Android?
- What is use of handler in Android?
- What are interfaces in Android?
- How can I get current activity?
Why do we pass context in Android?
It’s an abstract class whose implementation is provided by the Android system.
Context allows access to application-specific resources and classes, as well as calls for application-level operations such as launching activities, broadcasting and receiving intents, etc..
What are the different kinds of context in Android?
Mainly two types of context:Application Context: It is the application and we are present in Application. For example – MyApplication(which extends Application class). It is an instance of MyApplication only.Activity Context: It is the activity and we are present in Activity. For example – MainActivity.
What is getBaseContext in Android?
getBaseContext() is the method of ContextWrapper . And ContextWrapper is, “Proxying implementation of Context that simply delegates all of its calls to another Context. Can be subclassed to modify behavior without changing the original Context.” (as per javadocs)..
What is singleton class in Android?
A singleton is a design pattern that restricts the instantiation of a class to only one instance. Notable uses include controlling concurrency and creating a central point of access for an application to access its data store. This example demonstrate about How to use singleton class in android.
What is Android ViewGroup?
The ViewGroup class is a subclass of the View class. ViewGroup instances work as containers for View instances to group View instances together. Android contains the following commonly used ViewGroup subclasses: LinearLayout.
What is Android ContextWrapper?
Provides the central interface between an application and Android’s data backup infrastructure. ContextThemeWrapper. A ContextWrapper that allows you to modify the theme from what is in the wrapped context.
What is attachBaseContext?
The attachBaseContext function is ContextWrapper class is making sure the context is attached only once. ContextThemeWrapper which as its name, apply theme from application or Activity which is defined as ‘android:theme’ in AndroidManifest.
What is the difference between getApplicationContext and getBaseContext in Android?
getApplicationContext() – Returns the context for all activities running in application. getBaseContext() – If you want to access Context from another context within application you can access. getContext() – Returns the context view only current running activity.
Which database is used in Android?
SQLiteSince Android was created, we app developers have been using SQLite to store our local data. Sometimes directly with SQL statements, sometimes using an Object-Relational Mapper (ORM) as an abstraction layer, but either way, we’ve been using SQLite at the end of the day.
What is use of handler in Android?
A Handler allows you to send and process Message and Runnable objects associated with a thread’s MessageQueue . … There are two main uses for a Handler: (1) to schedule messages and runnables to be executed at some point in the future; and (2) to enqueue an action to be performed on a different thread than your own.
What are interfaces in Android?
An interface is a collection of abstract methods. A class implements an interface, thereby inheriting the abstract methods of the interface. An interface is not a class. … A class describes the attributes and behaviors of an object. An interface contains behaviors that a class implements.
How can I get current activity?
Android called “CurrentActivity”. Then if you want to access the current activity anywhere in your Android application, library, or plugin simply call: CrossCurrentActivity. Current. Activity and you will have the current activity.