Your Activity means you have to declare your each and every class in android manifest so that it recognizes them as the Activity.So after the end of the Activity main you can do following: How do you define activity in manifest?

To declare your activity, open your manifest file and add an <activity> element as a child of the <application> element. For example: <manifest … > The only required attribute for this element is android:name, which specifies the class name of the activity.

Which tag is used to define activities in manifest file?

Declares an activity (an Activity subclass) that implements part of the application’s visual user interface. All activities must be represented by <activity> elements in the manifest file. Any that are not declared there will not be seen by the system and will never be run.

Why do we need to define activity in the manifest?

Each android application you build will include a file called AndroidManifest. xml which is placed in the root of the project hierarchy. So why is it important? Because it lets you define the structure and metadata of your android application and its components.