- What is a context in Android?
- What are the types of layout in Android?
- Where are layouts placed in Android?
- What is the use of frame layout in Android?
- What are interfaces in Android?
- Which Android layout is best?
- What is the use of setOnClickListener in Android?
- Is Button a view in Android?
- What are Viewgroups and how they are different from the views?
- How do you kill an activity?
- What is view in Android with example?
- Why do we need context in Android?
- What are the types of broadcast receivers in Android?
- What are the 4 basic layout types?
- What is Android constraint layout?
- What is the R class in Android?
- How can use onClick method in Android?
- What are the different types of layouts in Android?
What is a context in Android?
What is Context in Android.
It is the context of the current state of the application.
It can be used to get information regarding the activity and application.
It can be used to get access to resources, databases, and shared preferences, and etc.
Both the Activity and Application classes extend the Context class..
What are the types of layout in Android?
Android Layout TypesSr.NoLayout & Description2Relative Layout RelativeLayout is a view group that displays child views in relative positions.3Table Layout TableLayout is a view that groups views into rows and columns.4Absolute Layout AbsoluteLayout enables you to specify the exact location of its children.4 more rows
Where are layouts placed in Android?
In Android, an XML-based layout is a file that defines the different widgets to be used in the UI and the relations between those widgets and their containers. Android treats the layout files as resources. Hence the layouts are kept in the folder reslayout.
What is the use of frame layout in Android?
FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that’s scalable to different screen sizes without the children overlapping each other.
What are interfaces in Android?
An interface is a reference type in Java. It is similar to class. It is a collection of abstract methods. A class implements an interface, thereby inheriting the abstract methods of the interface. Along with abstract methods, an interface may also contain constants, default methods, static methods, and nested types.
Which Android layout is best?
Use FrameLayout, RelativeLayout or a custom layout instead. Those layouts will adapt to different screen sizes, whereas AbsoluteLayout will not. I always go for LinearLayout over all other layout.
What is the use of setOnClickListener in Android?
setOnClickListener(this); means that you want to assign listener for your Button “on this instance” this instance represents OnClickListener and for this reason your class have to implement that interface. If you have more than one button click event, you can use switch case to identify which button is clicked.
Is Button a view in Android?
Button View in Android Button , as understood by its name, is a component which can be pressed or clicked by the user to perform an action. It has the same properties as a TextView , with a few Button specific properties.
What are Viewgroups and how they are different from the views?
A ViewGroup is a special view that can contain other views (called children.) The view group is the base class for layouts and views containers. … View is the base class for widgets, which are used to create interactive UI components (buttons, text fields, etc.).
How do you kill an activity?
9 Answers. You can also add android:noHistory=”true” to your Activity tag in AndroidManifest. xml . Yes, all you need to do is call finish() in any Activity you would like to close.
What is view in Android with example?
The View is a base class for all UI components in android. For example, the EditText class is used to accept the input from users in android apps, which is a subclass of View . Following are the some of common View subclasses that will be used in android applications.
Why do we need context in Android?
Context provide the connection to the Android system which executes the application. For example, you can check the size of the current device display via the Context. It also gives access to the resources of the project. It is the interface to global information about the application environment.
What are the types of broadcast receivers in Android?
There are two types of broadcasts received by receivers and they are:Normal Broadcasts: These are asynchronous broadcasts. Receivers of this type of broadcasts may run in any order, sometimes altogether. … Ordered Broadcasts. These are synchronous broadcasts. One broadcast is delivered to one receiver at a time.
What are the 4 basic layout types?
There are four basic types of layouts: process, product, hybrid, and fixed position. Process layouts group resources based on similar processes. Product layouts arrange resources in straight-line fashion. Hybrid layouts combine elements of both process and product layouts.
What is Android constraint layout?
A ConstraintLayout is a android. view. ViewGroup which allows you to position and size widgets in a flexible way. Note: ConstraintLayout is available as a support library that you can use on Android systems starting with API level 9 (Gingerbread).
What is the R class in Android?
Android R. java is an auto-generated file by aapt (Android Asset Packaging Tool) that contains resource IDs for all the resources of res/ directory. If you create any component in the activity_main. xml file, id for the corresponding component is automatically created in this file.
How can use onClick method in Android?
To define the click event handler for a button, add the android:onClick attribute to the
What are the different types of layouts in Android?
Common LayoutsLinear Layout. A layout that organizes its children into a single horizontal or vertical row. … Relative Layout. Enables you to specify the location of child objects relative to each other (child A to the left of child B) or to the parent (aligned to the top of the parent).Web View. … List View. … Grid View.