What is the meaning of android.intent.action.MAIN?

Issue

I have seen so many different confusing explenations..

<intent-filter>
     <action android:name="android.intent.action.MAIN" /> 
     <category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

What is the meaning of

<action android:name="android.intent.action.MAIN" />

and

 <category android:name="android.intent.category.LAUNCHER" />

and

 <category android:name="android.intent.category.DEFAULT" />

Solution

android.intent.action.MAIN means that this activity is the entry point of the application, i.e. when you launch the application, this activity is created.

From the docs

ACTION_MAIN with category CATEGORY_HOME -- Launch the home screen.

Also,from here

Activity Action Start as a main entry point, does not expect to receive data.

android.intent.category.DEFAULT is mainly used for implicit intents. If your activity wishes to be started by an implicit intent it should include this catetory in its filter. If your Activity might be started by an implicit Intent when no specific category is assigned to it, its Intent filter should include this category.

android.intent.category.LAUNCHER

category -- Gives additional information about the action to execute.

CATEGORY_LAUNCHER means it should appear in the Launcher as a top-level application

See the docs..

1. http://developer.android.com/reference/android/content/Intent.html
2. http://developer.android.com/guide/topics/manifest/action-element.html

Answered By - Lal