How to get the date of birth from the calender in android?

I am new in android. My layout is as:

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

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="26-01-2010" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Calender" />

</LinearLayout>

I have a Edit Box and button. When I click on the Button, I want to open a calender and be able to pick a date from calender. Also, the selected date has to be set to the Edit Box.

Call method SelectDate on textview or button or editext click

 private void SelectDate() {

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


    showDialog(DATE_PICKER_ID);

}

@Override
protected Dialog onCreateDialog(int id) {
    switch (id) {
        case DATE_PICKER_ID:

            // open datepicker dialog.
            // set date picker for current date
            // add pickerListener listner to date picker
            return new DatePickerDialog(this, pickerListener, year, month,day);
    }
    return null;
}

private DatePickerDialog.OnDateSetListener pickerListener = new DatePickerDialog.OnDateSetListener() {

    // when dialog box is closed, below method will be called.
    @Override
    public void onDateSet(DatePicker view, int selectedYear,
                          int selectedMonth, int selectedDay) {

        year  = selectedYear;
        month = selectedMonth;
        day   = selectedDay;

        // Show selected date
        birthdate_edt.setText(new StringBuilder().append(month + 1)
                .append("-").append(day).append("-").append(year)
                .append(" "));

    }
};