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How to work on Intent (part-1) in Android?

In this article, we are going to learn how to create more than one activity and work with intent in Android?
Submitted by Manu Jemini, on December 14, 2017

Intent is a very easy way to move the control from one activity to another. Intent provides very simple techniques to set it. For this tutorial to work, just create a new project with any name. You will get a default activity namely 'MainActivity', you can make use of it. Also, create another activity ‘SecondActivity’ and layout with the choice of your name.

Starting with your XML file - 1, drag and drop a TextView and Button from the widget section. In your XML file - 2, drag and drop a TextView from the widget section. There is no implication about the parent layout type. Make your layout the way you want it.

The second thing is your JAVA file -1. To begin with, you should import TextView and Button from the widget, this is done by adding this line import android.widget.TextView;. After that, in your activity, there would a default onCreate() function, this would be pre-set to use quickly. In your JAVA file–2 you should import TextView from the widget, this is done by adding this line import android.widget.TextView;.

Now, you would need to have a variable of type Intent, Button, TextView and set it with the reference of the corresponding layout objects in corresponding JAVA files with the layout file.

Your app with start with MainActivity and in this activity an event listener has been set (look at the code below) up. To start the SecondActivity use the following line.

Intent I=new Intent(MainActivity.this, SecondActivity.class);
startActivity(I);

Above line would do it. After doing everything up, your code should look like this. Connect an android device or run an ADV and then build you project to see the result.

Java file:

package com.example.hp.demo;

import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity
{
    TextView textview;
    Button B;
    Context ctx=this;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        B = (Button) findViewById(R.id.button);
        textview=(TextView)findViewById(R.id.textView);
        B.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent I=new Intent(MainActivity.this, SecondActivity.class);

            startActivity(I);

        }});
    }
}

XML file -1:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:weightSum="1">


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:text="Activity-1"
        android:id="@+id/textView"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Click"
        android:id="@+id/button"
        android:layout_below="@+id/textView"
        android:layout_alignParentStart="true" />
</RelativeLayout>

XML file -2:

<?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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.hp.demo.SecondActivity">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:text="Activity-2"
        android:id="@+id/textView"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true" />

</RelativeLayout>

Manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.hp.demo">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".SecondActivity"></activity>
    </application>

</manifest>

Output