ActionBar

 

//MainActivity

 

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.view.Menu;

import android.view.MenuItem;

import android.widget.TextView;

import android.widget.Toast;

 

public class MainActivity extends AppCompatActivity {

 

    TextView count;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

 

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.menu_main, menu);

        return true;

    }

 

    @Override

    public boolean onOptionsItemSelected(MenuItem item) { switch(item.getItemId()) {

        case R.id.add:

            //add the function to perform here

            Toast.makeText(getApplicationContext(),"Add",Toast.LENGTH_SHORT).show();

            return(true);

        case R.id.reset:

            //add the function to perform here

            Toast.makeText(getApplicationContext(),"Reset",Toast.LENGTH_SHORT).show();

            return(true);

        case R.id.about:

            //add the function to perform here

            Toast.makeText(getApplicationContext(),"About",Toast.LENGTH_SHORT).show();

            return(true);

        case R.id.exit:

            //add the function to perform here

            Toast.makeText(getApplicationContext(),"Exit",Toast.LENGTH_SHORT).show();

            return(true);

    }

        return(super.onOptionsItemSelected(item));

    }}

 

//activity_main.xml

 

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

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context=".MainActivity" >

</RelativeLayout>

 

 

//menu_main.xml

 

res -> New -> Android resource file -> File name -> menu_main.xml -> Resource type -> Menu

 

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

<menu xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:app="http://schemas.android.com/apk/res-auto"

    xmlns:tools="http://schemas.android.com/tools" tools:context=".MainActivity">

    <item

        android:id="@+id/add"

        app:showAsAction="never"

        android:title="add"/>

    <item

        android:id="@+id/reset"

        app:showAsAction="never"

        android:title="reset"/>

    <item

        android:id="@+id/about"

        app:showAsAction="never"

        android:title="about"/>

    <item

        android:id="@+id/exit"

        app:showAsAction="never"

        android:title="exit"/>

</menu>