Date picker in Android

public class dateresult extends Activity
{
private TextView tvdisplaydate;
private DatePicker dpResult;
private Button bntchangedate;

private int year;
private int month;
private int day;
static final int DATE_DIALOG_ID = 999;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.result);
    setCurrentdateonView();
    addListenerOnButton();

     }
              public void setCurrentdateonView(){

                  tvdisplaydate = (TextView)findViewById(R.id.tvdate);
                  dpResult = (DatePicker) findViewById(R.id.dpResult);

                  final Calendar c = Calendar.getInstance();
                  year = c.get(Calendar.YEAR);
                  month = c.get(Calendar.MONTH) ;
                  day = c.get(Calendar.DAY_OF_MONTH);

                  tvdisplaydate.setText(new StringBuffer()                   .append(month+1).append("-").append(day).append("-").append(year).append(""));
                  dpResult.init(year, month, day, null);                                  
              }             
             public void addListenerOnButton(){                  
                 bntchangedate = (Button)findViewById(R.id.bntchangedate);
                 bntchangedate.setOnClickListener(new OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        // TODO Auto-generated method stub
                    showDialog(DATE_DIALOG_ID);

                    }
                });              
             }                
             @Override
            protected Dialog onCreateDialog(int id) {
                // TODO Auto-generated method stub
                 switch(id){

                 case DATE_DIALOG_ID:
                     return new DatePickerDialog(this,datePickerLisner,year,month,day);

                 }
                return null;
            }                
             private DatePickerDialog.OnDateSetListener datePickerLisner = new DatePickerDialog.OnDateSetListener() {
                @Override
                public void onDateSet(DatePicker view, int Selectyear,int Selectmonth, int Selectday) {
                    year= Selectyear;
                    month= Selectmonth;
                    day = Selectday;
                    tvdisplaydate.setText(new StringBuilder() 
                    .append(Selectmonth+1).append("-").append(Selectday).append("-").append(Selectyear).append(""));
                            dpResult.init(year, month, day, null);                  
                }
            };
}


<?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" >

<Button
    android:id="@+id/bntchangedate"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Change Date" />

<TextView
    android:id="@+id/lbldate"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Current Date (M-D-YYYY) :" 
    android:textAppearance="?android:attr/textAppearanceLarge"/>

<TextView
    android:id="@+id/tvdate"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text=""
    android:textAppearance="?android:attr/textAppearanceLarge" />
<DatePicker
    android:id="@+id/dpResult"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

</LinearLayout>

Use the DatePicker

http://developer.android.com/reference/android/widget/DatePicker.html

It is availible since API Level 1

Here a example how to use the DatePickerDialog.

First add a TextView and a Button to your layout.xml

<Button android:id="@+id/myDatePickerButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Choose Date"/>

<TextView android:id="@+id/showMyDate"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"/>

Next you have to initialize the Button and TextView in the onCreate Method of your layout. You need this class variables

private int mYear;
private int mMonth;
private int mDay;

private TextView mDateDisplay;
private Button mPickDate;

static final int DATE_DIALOG_ID = 0;

Here the onCreate method

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    mDateDisplay = (TextView) findViewById(R.id.showMyDate);        
    mPickDate = (Button) findViewById(R.id.myDatePickerButton);

    mPickDate.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            showDialog(DATE_DIALOG_ID);
        }
    });

    // get the current date
    final Calendar c = Calendar.getInstance();
    mYear = c.get(Calendar.YEAR);
    mMonth = c.get(Calendar.MONTH);
    mDay = c.get(Calendar.DAY_OF_MONTH);

    // display the current date
    updateDisplay();
}

UpdateDisplay method:

private void updateDisplay() {
    this.mDateDisplay.setText(
        new StringBuilder()
                // Month is 0 based so add 1
                .append(mMonth + 1).append("-")
                .append(mDay).append("-")
                .append(mYear).append(" "));
}

The callback listener for the DatePickDialog

private DatePickerDialog.OnDateSetListener mDateSetListener =
    new DatePickerDialog.OnDateSetListener() {
        public void onDateSet(DatePicker view, int year, 
                              int monthOfYear, int dayOfMonth) {
            mYear = year;
            mMonth = monthOfYear;
            mDay = dayOfMonth;
            updateDisplay();
        }
    };

The onCreateDialog method, called by showDialog()

@Override
protected Dialog onCreateDialog(int id) {
   switch (id) {
   case DATE_DIALOG_ID:
      return new DatePickerDialog(this,
                mDateSetListener,
                mYear, mMonth, mDay);
   }
   return null;
}

Hope it helps, used it and it works fine.

Example from

http://developer.android.com/guide/tutorials/views/hello-datepicker.html

Here is an updated version which documents backwards compatibility with the Support Library:

http://developer.android.com/guide/topics/ui/controls/pickers.html#DatePicker