An Activity (calling-Activity) can spawn another Activity (sub-Activity) in 2 ways: Fire and forget – create an event (Intent) and fire it. Async callback – create an event (Intent), fire it, and wait for it’s response in a callback method (of the calling-Activity).
What is sub activity?
In android as @Ted mentioned above activity started from another activity can be considered as sub activity. Also Fragments are generally regarded as sub-activity having their own lifecycle closely tied to the hosting activity.
What is an activity in Android?
An activity represents a single screen with a user interface just like window or frame of Java. Android activity is the subclass of ContextThemeWrapper class. If you have worked with C, C++ or Java programming language then you must have seen that your program starts from main() function.
How many types of activity are there in Android?
Three of the four component types—activities, services, and broadcast receivers—are activated by an asynchronous message called an intent. Intents bind individual components to each other at runtime.
What is Intentfilter?
An intent filter is an expression in an app’s manifest file that specifies the type of intents that the component would like to receive. For instance, by declaring an intent filter for an activity, you make it possible for other apps to directly start your activity with a certain kind of intent.
What is Android activity life cycle?
An activity is the single screen in android. … It is like window or frame of Java. By the help of activity, you can place all your UI components or widgets in a single screen. The 7 lifecycle method of Activity describes how activity will behave at different states.
What is Android default activity?
In Android, you can configure the starting activity (default activity) of your application via following “intent-filter” in “AndroidManifest. xml“. See following code snippet to configure a activity class “logoActivity” as the default activity.
What are the different types of layouts in Android?
Types of Layouts in Android
- Linear Layout.
- Relative Layout.
- Constraint Layout.
- Table Layout.
- Frame Layout.
- List View.
- Grid View.
- Absolute Layout.
How do you kill an activity?
Launch your application, open some new Activity, do some work. Hit the Home button (application will be in the background, in stopped state). Kill the Application — easiest way is to just click the red “stop” button in Android Studio. Return back to your application (launch from Recent apps).
What are the main components in Android?
Introduction. There are four main Android app components: activities , services , content providers , and broadcast receivers . Whenever you create or use any of them, you must include elements in the project manifest.
Which Android activity has highest priority?
In other word, if you have two activities each having an intent filter with the same action and category, then any Intent sent (from a 3rd party app) with those action/category details, will be passed first to the Activity whose intent filter has the highest priority.
What is the purpose of the IntentFilter class?
An intent filter is an instance of the IntentFilter class. Intent filters are helpful while using implicit intents, It is not going to handle in java code, we have to set it up in AndroidManifest.
What is broadcast receiver in android?
Definition. A broadcast receiver (receiver) is an Android component which allows you to register for system or application events. All registered receivers for an event are notified by the Android runtime once this event happens.