DatePicker sample (Android)

inflate_dialog_select_date.xml

<?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"
    android:padding="16dip" >

    <DatePicker
        android:id="@+id/datePicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:calendarViewShown="false"
        android:spinnersShown="true" />

</LinearLayout>

SelectDateDialogFragment.java

public class SelectDateDialogFragment extends DialogFragment {

    public static DialogFragment newInstance() {
        Bundle args = new Bundle();

        DialogFragment fragment = new SelectDateDialogFragment();
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // 表示日付
        Date initDate = new Date();

        AlertDialog.Builder builder = new Builder(getActivity());
        builder.setView(createView(initDate));
        builder.setPositiveButton("選択", new OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                okProcess();
            }
        });
        builder.setNegativeButton("キャンセル", new OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                cancelProcess();
            }
        });
        return builder.create();
    }

    private DatePicker mDatePicker;

    private View createView(final Date date) {
        View view = getActivity().getLayoutInflater().inflate(R.layout.inflate_dialog_select_date, null, false);

        // 日付設定
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int year = cal.get(Calendar.YEAR);
        int month = cal.get(Calendar.MONTH);
        int dayOfMonth = cal.get(Calendar.DAY_OF_MONTH);

        mDatePicker = (DatePicker) view.findViewById(R.id.datePicker);
        mDatePicker.updateDate(year, month, dayOfMonth);
        return view;
    }

    private void okProcess() {
        if (mDatePicker == null) {
            return;
        }
        int year = mDatePicker.getYear();
        int month = mDatePicker.getMonth();
        int dayOfMonth = mDatePicker.getDayOfMonth();
        String selectedDate = String.format("%d/%d/%d", year, month + 1, dayOfMonth);
        CareSupportUtil.showToast(getActivity(), selectedDate);
    }

    private void cancelProcess() {
    }
}