Creating a Menu in an Activity

To define your own menu, create an XML file inside your project’s res/menu/ directory and build the menu with the following elements:

<menu> : Defines a Menu, which holds all the menu items.
<item> : Creates a MenuItem, which represents a single item in a menu. We can also create a nested element in order to create a submenu.

Step 1:

Create your own xml file as the following:

In res/menu/main_menu.xml:

<?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/aboutMenu"
        android:title="About" />
    <item
        android:id="@+id/helpMenu"
        android:title="Help" />
    <item
        android:id="@+id/signOutMenu"
        android:title="Sign Out" />
</menu>

Step 2:

To specify the options menu, override onCreateOptionsMenu() in your activity.

In this method, you can inflate your menu resource (defined in your XML file i.e., res/menu/main_menu.xml)

@Override
   public boolean onCreateOptionsMenu(Menu menu) {
       MenuInflater inflater = getMenuInflater();
       inflater.inflate(R.menu.main_menu, menu);
       return true;
   }

When the user selects an item from the options menu, the system calls your activity’s overridden onOptionsItemSelected() method.

This method passes the MenuItem selected.
You can identify the item by calling getItemId(), which returns the unique ID for the menu item (defined by the android:id attribute in the menu resource - res/menu/main_menu.xml)*/

@Override
public boolean onOptionsItemSelected(MenuItem item) {
   switch (item.getItemId()) {
       case R.id.aboutMenu:
           Log.d(TAG, "Clicked on About!");
           // Code for About goes here
           return true;
       case R.id.helpMenu:
           Log.d(TAG, "Clicked on Help!");
           // Code for Help goes here
           return true;
       case R.id.signOutMenu:
           Log.d(TAG, "Clicked on Sign Out!");
           // SignOut method call goes here
           return true;
       default:
           return super.onOptionsItemSelected(item);
   }
}

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Wrapping up!

Your Activity code should look like below:

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "mytag";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.aboutMenu:
                Log.d(TAG, "Clicked on About!");
                // Code for About goes here
                return true;
            case R.id.helpMenu:
                Log.d(TAG, "Clicked on Help!");
                // Code for Help goes here
                return true;
            case R.id.signOutMenu:
                Log.d(TAG, "User signed out");
                // SignOut method call goes here
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}

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