Android Tutorial

You have learnt Android Intent, which is an object carrying an intent ie. message from one component to another component with-in the application or outside the application.

As such you do not need to develop your email client from scratch because they are already available like Gmail and K9mail. But you will need to send email from your Android application, where you will have to write an Activity that needs to launch an email client and sends an email using your Android device. For this purpose, your Activity will send an ACTION_SEND along with appropriate data load, to the Android Intent Resolver. The specified chooser gives the proper interface for the user to pick how to send your email data.

Following section explains different parts of our Intent object required to send an email.

Intent Object - Action to send Email

You will use ACTION_SEND action to launch an email client installed on your Android device. Following is simple syntax to create an intent with ACTION_SEND action

Intent emailIntent = new Intent(Intent.ACTION_SEND);

Intent Object - Data/Type to send Email

To send an email you need to specify mailto: as URI using setData() method and data type will be totext/plain using setType() method as follows:

emailIntent.setData(Uri.parse("mailto:"));
emailIntent.setType("text/plain");

Intent Object - Extra to send Email

Android has built-in support to add TO, SUBJECT, CC, TEXT etc. fields which can be attached to the intent before sending the intent to a target email client. You can use following extra fields in your email:

S.N.	Extra Data & Description
1	EXTRA_BCC  A String[] holding e-mail addresses that should be blind carbon copied.
2	EXTRA_CC  A String[] holding e-mail addresses that should be carbon copied.
3	EXTRA_EMAIL  A String[] holding e-mail addresses that should be delivered to.
4	EXTRA_HTML_TEXT  A constant String that is associated with the Intent, used with ACTION_SEND to supply an alternative to EXTRA_TEXT as HTML formatted text.
5	EXTRA_SUBJECT  A constant string holding the desired subject line of a message.
6	EXTRA_TEXT  A constant CharSequence that is associated with the Intent, used with ACTION_SEND to supply the literal data to be sent.
7	EXTRA_TITLE  A CharSequence dialog title to provide to the user when used with a ACTION_CHOOSER.

Here is an example showing you how to assign extra data to your intent:

emailIntent.putExtra(Intent.EXTRA_EMAIL  , new String[]{"recipient@example.com"});
emailIntent.putExtra(Intent.EXTRA_SUBJECT, "subject of email");
emailIntent.putExtra(Intent.EXTRA_TEXT   , "body of email");

Example

Following example shows you in practical how to use Intent object to launch Email client to send an Email to the given recipients.

To experiment with this example, you will need actual Mobile device equipped with latest Android OS, otherwise you will have to struggle with emulator which may not work. Second you will need to have an Email client like GMail or K9mail installed on your device.

Step	Description
1	You will use Eclipse IDE to create an Android application and name it as SendEmailDemounder a package com.example.sendemaildemo. While creating this project, make sure youTarget SDK and Compile With at the latest version of Android SDK to use higher levels of APIs.
2	Modify src/MainActivity.java file and add required code to take care of sending email.
3	Modify layout XML file res/layout/activity_main.xml add any GUI component if required. I'm adding a simple button to launch Email Client.
4	Modify res/values/strings.xml to define required constant values
5	Modify AndroidManifest.xml as shown below
6	Run the application to launch Android emulator and verify the result of the changes done in the aplication.

Following is the content of the modified main activity filesrc/com.example.sendemaildemo/MainActivity.java.

package com.example.sendemaildemo;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      Button startBtn = (Button) findViewById(R.id.sendEmail);
      startBtn.setOnClickListener(new View.OnClickListener() {
         public void onClick(View view) {
         sendEmail();
      }
   });

   }
   protected void sendEmail() {
      Log.i("Send email", "");

      String[] TO = {"amrood.admin@gmail.com"};
      String[] CC = {"mcmohd@gmail.com"};
      Intent emailIntent = new Intent(Intent.ACTION_SEND);
      emailIntent.setData(Uri.parse("mailto:"));
      emailIntent.setType("text/plain");


      emailIntent.putExtra(Intent.EXTRA_EMAIL, TO);
      emailIntent.putExtra(Intent.EXTRA_CC, CC);
      emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Your subject");
      emailIntent.putExtra(Intent.EXTRA_TEXT, "Email message goes here");

      try {
         startActivity(Intent.createChooser(emailIntent, "Send mail..."));
         finish();
         Log.i("Finished sending email...", "");
      } catch (android.content.ActivityNotFoundException ex) {
         Toast.makeText(MainActivity.this, 
         "There is no email client installed.", Toast.LENGTH_SHORT).show();
      }
   }
   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
      // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.main, menu);
      return true;
   }
}

Following will be the content of res/layout/activity_main.xml file:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >

   <Button android:id="@+id/sendEmail"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:text="@string/compose_email"/>
    
</LinearLayout>

Following will be the content of res/values/strings.xml to define two new constants:

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

    <string name="app_name">SendEmailDemo</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>
    <string name="compose_email">Compose Email</string>

</resources>

Following is the default content of AndroidManifest.xml:

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

Let's try to run your SendEmailDemo application. I assume you have connected your actual Android Mobile device with your computer. To run the app from Eclipse, open one of your project's activity files and click Run  icon from the toolbar. Before starting your application, Eclipse will display following window to select an option where you want to run your Android application.

Select your mobile device as an option and then check your mobile device which will display following screen:

Now use Compose Email button to list down all the installed email clients. From the list, you can choose one of email clients to send your email. I'm going to use Gmail client to send my email which will have all the provided defaults fields available as shown below. Here From: will be default email ID you have registered for your Android device.

You can modify either of the given default fields and finally use send email button (marked with red rectangle) to send your email to the mentioned recipients.