Third Case of Intent in Android

Intent
An intent is an abstract description of an operation to be performed. In simple words we can say that an intent is basically used to notify the Android system of the occurrence of an event.

Procedure

1. Start the Eclipse IDE.
2. Create a new project.
3. Create two Java files, one is MainActivity.java file and the other one is B.java.
4. Create two XML files, one is the activity_main.xml file and the second is ll.xml for layout design.
5. In the third case of intent we add an activity with an intent filter to the manifest file like this:
   
   <activity android:name="B"></activity>
    
6. In the MainActivity.java file make an intent with an extra string like this:
   
   Intent i=new Intent(getApplicationContext(),B.class);
   i.putExtra("money", e1.getText().toString());
   startActivity(i);
    
7. In the B.java file within the onCreate function use a getIntent with getStringExtra like this:
   
   Intent i=getIntent();
   String str=i.getStringExtra("money");
   tv.setText(str);
   
   Code is given below
   MainActivity.java:
   package com.example.intentcase3rd;
   import android.os.Bundle;
   import android.app.Activity;
   import android.content.Intent;
   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;
       Button b1;
      @Override
     protected void onCreate(Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         e1=(EditText)findViewById(R.id.editText1);
         b1=(Button)findViewById(R.id.button1);
         b1.setOnClickListener(this);
      }
       public void onClick(View v)
       {
            // TODO Auto-generated method stub
            Intent i=new Intent(getApplicationContext(),B.class);
            i.putExtra("money", e1.getText().toString());
            startActivity(i);
        }
   } 
   
   B.java
   package com.example.intentcase3rd;
   import android.app.Activity;
   import android.content.Intent;
   import android.os.Bundle;
   import android.view.View;
   import android.view.View.OnClickListener;
   import android.widget.Button;
   import android.widget.TextView;
   
   public class B extends Activity implements OnClickListener
   {
         TextView tv;
         Button b1;
         @Override
         protected void onCreate(Bundle savedInstanceState)
        {
              // TODO Auto-generated method stub
              super.onCreate(savedInstanceState);
              setContentView(R.layout.ll);
              tv=(TextView)findViewById(R.id.textView1);
              Intent i=getIntent();
              String str=i.getStringExtra("money");
              tv.setText(str);
              b1=(Button)findViewById(R.id.button1);
              b1.setOnClickListener(this);                       
         }
         public void onClick(View v)
         {
              // TODO Auto-generated method stub                       
         }
   }
   
   activity_main.xml
    
   <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=".MainActivity" >
     <TextView
         android:id="@+id/textView1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Intent3 Demo" />
     <EditText
         android:id="@+id/editText1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentRight="true"
         android:layout_below="@+id/textView1"
         android:layout_marginRight="54dp"
         android:layout_marginTop="53dp"
         android:ems="10" >
      
       <requestFocus />
     </EditText> 
     <Button
         android:id="@+id/button1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_below="@+id/editText1"
         android:layout_marginLeft="18dp"
         android:layout_marginTop="31dp"
         android:layout_toRightOf="@+id/textView1"
         android:text="Send" /> 
   </RelativeLayout>
   
   ll.xml
    
   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:orientation="vertical" >
      
     <TextView
         android:id="@+id/textView1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Large Text"
         android:textAppearance="?android:attr/textAppearanceLarge" />
      
     <Button
         android:id="@+id/button1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Ok" />
   </LinearLayout>
   
   
   intentcase3rd Manifest
    
   <?xml version="1.0" encoding="utf-8"?>
   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
       package="com.example.intentcase3rd"
       android:versionCode="1"
       android:versionName="1.0" >
      
     <uses-sdk
         android:minSdkVersion="8"
         android:targetSdkVersion="17" />
      
     <application
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
       <activity
           android:name="com.example.intentcase3rd.MainActivity"
           android:label="@string/app_name" >
         <intent-filter>
           <action android:name="android.intent.action.MAIN" />
            
           <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
       </activity>
       <activity android:name="B"></activity>
     </application>
   </manifest>

Output

 

 

By clicking on the Send button it is intented to another activity as in the following: