DatePickerDialog

workspace/DatePicker/res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 >
<TextView
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="@string/hello"
 />
<Button
 android:id="@+id/startdatepicker"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:text="Start DatePicker"
 />
</LinearLayout>

workspace/DatePicker/src/com/DatePicker/DatePicker.java

package com.DatePicker;

import java.util.Calendar;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class DatePicker extends Activity {
 
 private int year, month, day;
 static final int ID_DATEPICKER = 0;
 
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.main);
  
     Button startDatePicker = (Button)findViewById(R.id.startdatepicker);
     startDatePicker.setOnClickListener(new Button.OnClickListener(){

   @Override
   public void onClick(View arg0) {
    // TODO Auto-generated method stub
    final Calendar c = Calendar.getInstance();
       year = c.get(Calendar.YEAR);
       month = c.get(Calendar.MONTH);
       day = c.get(Calendar.DAY_OF_MONTH);
       showDialog(ID_DATEPICKER);
   }});
 }

 @Override
 protected Dialog onCreateDialog(int id) {
  // TODO Auto-generated method stub
  switch(id){
  case ID_DATEPICKER:
   return new DatePickerDialog(this, dateSetListener, year, month, day);
  default:
   return null;
  }
 }
 
 private DatePickerDialog.OnDateSetListener dateSetListener
   = new DatePickerDialog.OnDateSetListener(){

  @Override
  public void onDateSet(android.widget.DatePicker arg0, int arg1,
    int arg2, int arg3) {
   // TODO Auto-generated method stub

      Toast.makeText(getBaseContext(),
        String.valueOf(arg1) + "/"
        + String.valueOf(arg2+1) + "/"
        + String.valueOf(arg3),
        Toast.LENGTH_LONG).show();
     }
  };
}