android datepicker只显示年跟日期

public class YearMonthPicker extends DatePickerDialog {	public YearMonthPicker(Context context, int theme,			OnDateSetListener callBack, int year, int monthOfYear,			int dayOfMonth) {		super(context, theme, callBack, year, monthOfYear, dayOfMonth);		init(year, monthOfYear, dayOfMonth);	}	public YearMonthPicker(Context context, OnDateSetListener callBack,			int year, int monthOfYear, int dayOfMonth) {		super(context, callBack, year, monthOfYear, dayOfMonth);		init(year, monthOfYear, dayOfMonth);	}	private void init(int year, int month, int dayOfMonth) {		hideDayView();		hideCalendarView();		setTitle(year, month);	}		@SuppressLint("NewApi")	private void hideCalendarView(){		if (android.os.Build.VERSION.SDK_INT >= 11) { 			getDatePicker().setCalendarViewShown(false);		}	}	@Override	public void onDateChanged(DatePicker view, int year, int month, int day) {		super.onDateChanged(view, year, month, day);		setTitle(year, month);	}	private void setTitle(int year, int month) {		month += 1;		String yearStr = String.valueOf(year);		String monthStr = (month < 10) ? ("0" + month) : ("" + month);		setTitle(yearStr + "/" + monthStr);	}	private void hideDayView() {		try {			Field[] datePickerDialogFields = getClass().getSuperclass()					.getDeclaredFields();			for (Field datePickerDialogField : datePickerDialogFields) {				if (datePickerDialogField.getName().equals("mDatePicker")) {					datePickerDialogField.setAccessible(true);					DatePicker datePicker = (DatePicker) datePickerDialogField							.get(this);					Field datePickerFields[] = datePickerDialogField.getType()							.getDeclaredFields();					for (Field datePickerField : datePickerFields) {						if ("mDayPicker".equals(datePickerField.getName())								|| "mDaySpinner".equals(datePickerField										.getName())) {							datePickerField.setAccessible(true);							Object dayPicker = new Object();							dayPicker = datePickerField.get(datePicker);							((View) dayPicker).setVisibility(View.GONE);						}					}				}			}		} catch (Exception ex) {			ex.printStackTrace();		}	}}