- How do I change content view on Android?
- What is the use of intent in android?
- What is the purpose of setContentView () function?
- What are Android activities?
- What is the use of onCreate method in Android?
- Why do we need to call setContentView () in onCreate () of activity class?
- What is the R class in Android?
- How can I make my Android button more attractive?
- How do I use onPause in Android?
- What does setOnClickListener do in Android?
- Why we use find view by ID in android?
- What are the applications of Android?
- What is the use of savedInstanceState in Android?
- What is onResume method in Android?
- How can use onClick method in Android?
- Can I create activity without XML file?
- What is R layout?
- How many types of services are there in Android?
How do I change content view on Android?
You can call setContentView at any time*, not just in onCreate .
Just define all the views you want in separate XML files and pass the relevant id when it’s time to switch.
If you want to define the new layout dynamically in code, then do that and call setContentView and pass the root view of your new layout..
What is the use of intent in android?
Intents are used to signal to the Android system that a certain event has occurred. Intents often describe the action which should be performed and provide data upon which such an action should be done. For example, your application can start a browser component for a certain URL via an intent.
What is the purpose of setContentView () function?
Actually setContentView() is a method part of android. app. Activity class. It helps to set our content or render our layout on the screen.
What are Android activities?
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.
What is the use of onCreate method in Android?
onCreate() On activity creation, the activity enters the Created state. In the onCreate() method, you perform basic application startup logic that should happen only once for the entire life of the activity.
Why do we need to call setContentView () in onCreate () of activity class?
As onCreate() of an Activity is called only once, this is the point where most initialization should go: calling setContentView(int) to inflate the activity’s UI, using findViewById to programmatically interact with widgets in the UI, calling managedQuery(android.
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 I make my Android button more attractive?
Change button colorsUse tint to change color. … Change the color of the text. … Set color as a background. … Using custom color for a button. … Gradient background for a button. … Buttons with rounded corners. … Change the shape of a button – Circle button. … Images in buttons.More items…
How do I use onPause in Android?
onPause(): This method gets called when the UI is partially visible to the user. If a dialog is opened on the activity then the activity goes to pause state and calls onPause() method. Here the activity is in the paused state. onStop(): This method gets called when the UI is not visible to the user.
What does setOnClickListener do in Android?
OnClickListener and wires the listener to the button using setOnClickListener(View. OnClickListener) . As a result, the system executes the code you write in onClick(View) after the user presses the button. The system executes the code in onClick on the main thread.
Why we use find view by ID in android?
The binding process makes a single pass on all Views in the layout to assign the views to the fields. When you run findViewById, the view hierarchy is walked each time to find it. … If you aren’t attaching the inflated View to the containing ViewGroup, you’ll have to get access to the inflated View hierarchy.
What are the applications of Android?
Features of AndroidSr.No.Feature & Description1Beautiful UI Android OS basic screen provides a beautiful and intuitive user interface.2Connectivity GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC and WiMAX.3Storage SQLite, a lightweight relational database, is used for data storage purposes.10 more rows
What is the use of savedInstanceState in Android?
The savedInstanceState is a reference to a Bundle object that is passed into the onCreate method of every Android Activity. Activities have the ability, under special circumstances, to restore themselves to a previous state using the data stored in this bundle.
What is onResume method in Android?
onResume() is one of the methods called throughout the activity lifecycle. onResume() is the counterpart to onPause() which is called anytime an activity is hidden from view, e.g. if you start a new activity that hides it. onResume() is called when the activity that was hidden comes back to view on the screen.
How can use onClick method in Android?
To define the click event handler for a button, add the android:onClick attribute to the
Can I create activity without XML file?
If you don’t want Android to Studio to generate the xml files for you, You must do every steps on your own. Create a java class which extends from activity. Override OnCreate method in your activity and set your layout.
What is R layout?
In Android R is an Java-class that is auto-generated from your resources by the build process. The R. layout member is a auto-generated class that contains all IDs for layouts.
How many types of services are there in Android?
four different typesThere are four different types of Android services: Bound Service – A bound service is a service that has some other component (typically an Activity) bound to it. A bound service provides an interface that allows the bound component and the service to interact with each other.