The main activity code is a Java file MainActivity.java. This is the actual application file which ultimately gets converted to a Dalvik executable and runs your application. Following is the default code generated by the application wizard for Hello World! application − package com.

What is main activity in Android?

Generally, one activity implements one screen in an app. … Typically, one activity in an app is specified as the main activity, which is the first screen to appear when the user launches the app. Each activity can then start another activity in order to perform different actions.

What is MainActivity class in Android?

In Mobile SDK apps, the main activity begins immediately after the user logs in. Once the main activity is running, it can launch other activities, which in turn can launch sub-activities. The template app’s MainActivity class extends the abstract Mobile SDK activity class, com. …