DatePickerDialog in Android

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/chooseDateButton"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:text="Choose Date"
        android:textSize="20dp" />

    <TextView
        android:id="@+id/displatext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge" />

</LinearLayout>

MainActivity.java

package in.blogspot.kantapp.datepickerdialoginandroid;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.DatePickerDialog.OnDateSetListener;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;

import java.util.Calendar;

public class MainActivity extends Activity {
    Calendar c = Calendar.getInstance();
    TextView display;
    int cday, cmonth, cyear;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button changeDate = (Button) findViewById(R.id.chooseDateButton);
        display = (TextView) findViewById(R.id.displatext);

        changeDate.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                new DatePickerDialog(MainActivity.this, d,
                        c.get(Calendar.YEAR), c.get(Calendar.MONTH), c
                        .get(Calendar.DAY_OF_MONTH)).show();

            }
        });
    }

    DatePickerDialog.OnDateSetListener d = new OnDateSetListener() {

        @Override
        public void onDateSet(DatePicker view, int year, int monthOfYear,
                              int dayOfMonth) {

            cday = dayOfMonth;
            cmonth = monthOfYear + 1;
            cyear = year;

            display.setText("Choosen date is :" + cday + "/" + cmonth + "/"
                    + cyear);
        }
    };
}