A simple program to add two numbers in android

Introduction

 

A simple program to add two numbers in Android.

 

Procedure

1. Start Eclipse IDE.
2. Create a new project.
3. Create a MainActivity.java file.
4. Create an activity_main.xml file for layout design.
5. Add a button and three TextView fields in the XML layout.
6. Then look up the button and EditText fields by their ids in the MainActivity.java file.
7. Then define an additional code in the onClick function.

The following is the code.

 

MainActivity.java

package com.example.additionof2no;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends Activity implements OnClickListener {
 EditText e1, e2, e3;
 Button b1;
 double d1, d2, d3;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  b1 = (Button) findViewById(R.id.b2);
  e1 = (EditText) findViewById(R.id.e1);
  e2 = (EditText) findViewById(R.id.e2);
  e3 = (EditText) findViewById(R.id.e3);
  b1.setOnClickListener(this);
 }
 public void onClick(View v) {
  d1 = Double.parseDouble(e1.getText().toString());
  d2 = Double.parseDouble(e2.getText().toString());
  d3 = d1 + d2;
  e3.setText(Double.toString(d3));
 }
}

activity_main.xml

<LinearLayout
    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"
    android:background="@drawable/hydrangeas"
    android:orientation="vertical"
     >

    <LinearLayout android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

        <TextView android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="FN"/>

        <EditText android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/e1"
        android:hint="Enter First Number"/>

    </LinearLayout>

    <LinearLayout android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

        <TextView android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="SN"/>

        <EditText android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/e2"
        android:hint="Enter Second Number"/>

    </LinearLayout>

    <LinearLayout android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

        <TextView android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Result"/>

        <EditText android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/e3"
        android:hint="Result is here"/>

    </LinearLayout>

    <LinearLayout android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

        <Button android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/b2"
android:text="Click here to add"/>

    </LinearLayout>

</LinearLayout>

 

Output