Jan 13, 2017·5 min read. Launch mode is an instruction for Android OS which specifies how the activity should be launched. It instructs how any new activity should be associated with the current task.
What is Android launchMode singleTask?
An Activity with singleTask launchMode is allowed to have only one instance in the system (a.k.a. Singleton). If there is an existed Activity instance in the system, the whole Task hold the instance would be moved to top while Intent would be delivered through onNewIntent() method.
What is affinity in Android?
The affinity indicates which task an activity prefers to belong to. By default, all the activities from the same app have an affinity for each other. So, by default, all activities in the same app prefer to be in the same task. However, you can modify the default affinity for an activity.
What are Android activities?
An Android activity is one screen of the Android app’s user interface. In that way an Android activity is very similar to windows in a desktop application. An Android app may contain one or more activities, meaning one or more screens.
What is Android label in manifest?
android:label. A user-readable label for the activity. The label is displayed on-screen when the activity must be represented to the user. It’s often displayed along with the activity icon.
What is singleTop in Android?
singleTop
Using this launch mode you can create multiple instance of the same activity in the same task or in different tasks only if the same instance does not already exist at the top of stack. <activity android_launchMode=”singleTop” />
What is intent flag in Android?
Use Intent Flags
Intents are used to launch activities on Android. You can set flags that control the task that will contain the activity. Flags exist to create a new activity, use an existing activity, or bring an existing instance of an activity to the front.
How do you delete old activity on Android?
FLAG_ACTIVITY_CLEAR_TASK|Intent. FLAG_ACTIVITY_NEW_TASK); this. startActivity(intent); It will totally clears all previous activity(s) and start new activity.
What are the main two types of thread in Android?
Threading in Android
- AsyncTask. AsyncTask is the most basic Android component for threading. …
- Loaders. Loaders are the solution for the problem mentioned above. …
- Service. …
- IntentService. …
- Option 1: AsyncTask or loaders. …
- Option 2: Service. …
- Option 3: IntentService. …
- Option 1: Service or IntentService.
What is a fragment in Android?
A fragment is an independent Android component which can be used by an activity. A fragment encapsulates functionality so that it is easier to reuse within activities and layouts. A fragment runs in the context of an activity, but has its own life cycle and typically its own user interface.
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).
When onPause method is called in Android?
onPause. Called when the Activity is still partially visible, but the user is probably navigating away from your Activity entirely (in which case onStop will be called next). For example, when the user taps the Home button, the system calls onPause and onStop in quick succession on your Activity .
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.
What is use of manifest file in Android?
The manifest file describes essential information about your app to the Android build tools, the Android operating system, and Google Play. Among many other things, the manifest file is required to declare the following: The app’s package name, which usually matches your code’s namespace.
What is Android exported true?
android:exported Whether or not the broadcast receiver can receive messages from sources outside its application — “true” if it can, and “false” if not. If “false”, the only messages the broadcast receiver can receive are those sent by components of the same application or applications with the same user ID.
What is XML file in Android?
XML stands for Extensible Mark-up Language. XML is a very popular format and commonly used for sharing data on the internet. This chapter explains how to parse the XML file and extract necessary information from it. Android provides three types of XML parsers which are DOM,SAX and XMLPullParser.