What is Intent in android ? How to pass data using Intent ?

In android to pass data between activity Intent is used. You can use Intent.putExtras() in sender activity and Intent.getExtras() in receiving activity.


 Following Example explain intent in android.


 For this example we create two xml files main.xml and receiver.xml and we create two corresponding java files AndroidIntentExampleActivity.java and ReceiverActivity.java.

 Following are step by step explanation for this.



 step 1 :-  Create main.xml file. we create two TextView and one EditText and one Button.

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

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:gravity="center"
        android:text="@string/hello" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:text="@string/enterdata"
        android:text />

    <EditText
        android:id="@+id/enteryourdata"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:hint="Enter data"
        android:padding="5dp" />

    <Button
        android:id="@+id/btnok"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:layout_marginRight="15dp"
        android:text="Next" />

</LinearLayout>





  step 2 :-  Now corresponding to main.xml create one java file AndroidIntentExampleActivity.java which handles events.

  public class AndroidIntentExampleActivity extends Activity implements
        OnClickListener {

    EditText txtdata;
    Button btnok;
    String datatopass;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        txtdata = (EditText) findViewById(R.id.enteryourdata);
        btnok = (Button) findViewById(R.id.btnok);
        datatopass = txtdata.getText().toString();
        btnok.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        Intent intent = new Intent(AndroidIntentExampleActivity.this,ReceiverActivity.class);
        Bundle b = new Bundle();
        b.putString("data", txtdata.getText().toString());
        intent.putExtras(b);
        startActivity(intent);

    }
}


 Step 3 :- Now for receive data you need to create one xml file and one Java file. First create one xml file receiver.xml which display data passed  from first activity.

  receiver.xml

  <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@android:color/white"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/displaytext"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Text" android:gravity="center"
        android:textColor="@android:color/black"
        android:textSize="20dp"
        android:text />

</LinearLayout>
 
  Here TextView display the text which is passed from first activity. Now for handling events create java file ReceiverActivity.java



 step 4 :- Create ReceiverActivity.java

public class ReceiverActivity extends Activity {
    TextView txtdata;
    String value;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.receiver);
        txtdata = (TextView) findViewById(R.id.displaytext);
        Bundle extras = getIntent().getExtras();
        if (extras != null) {
            value = String.valueOf(extras.getString("data"));
            Toast.makeText(ReceiverActivity.this, "" + value, Toast.LENGTH_LONG)
                    .show();
            txtdata.setText(value);
        }
    }
}