日期选择器 利用NumberPicker

public class XcyDatePicker extends LinearLayout {    private static final int MIN_YEAR = 1900;    private int MAX_YEAR = 2016;    private static final int MIN_MONTH = 1;    private static final int MAX_MONTH = 12;    private NumberPicker yearNp;    private NumberPicker monthNp;    private NumberPicker dayNp;    public XcyDatePicker(Context context) {        super(context);        init(context);    }    public XcyDatePicker(Context context, AttributeSet attrs) {        super(context, attrs);        init(context);    }    public XcyDatePicker(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        init(context);    }    private void init(Context context) {        LayoutInflater.from(context).inflate(R.layout.xcy_date_picker, this);        yearNp = (NumberPicker) findViewById(R.id.year_np);        monthNp = (NumberPicker) findViewById(R.id.month_np);        dayNp = (NumberPicker) findViewById(R.id.day_np);        //初始化显示的日期 默认今天        setNpMinValAndMaxVal(yearNp, MIN_YEAR, MAX_YEAR);        setNpMinValAndMaxVal(monthNp, MIN_MONTH, MAX_MONTH);        setDisplayValue(new Date());        monthNp.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {            @Override            public void onValueChange(NumberPicker picker, int oldVal, int newVal) {                dayNp.setMaxValue(getDaysInMonthAndYear(yearNp.getValue(), newVal));            }        });        yearNp.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {            @Override            public void onValueChange(NumberPicker picker, int oldVal, int newVal) {                dayNp.setMaxValue(getDaysInMonthAndYear(newVal, monthNp.getValue()));            }        });    }    /**     * 获取某一年某一月的天数     *     * @param year     * @param month 取值范围1-12     * @return     */    private int getDaysInMonthAndYear(int year, int month) {        Calendar calendar = Calendar.getInstance();        calendar.set(Calendar.YEAR, year);        calendar.set(Calendar.MONTH, month - 1);        return calendar.getActualMaximum(Calendar.DATE);    }    /**     * 根据date来展示当前显示的日期     *     * @param date     */    public void setDisplayValue(Date date) {        Calendar calendar = Calendar.getInstance();        calendar.setTime(date);        yearNp.setValue(calendar.get(Calendar.YEAR));        monthNp.setValue(calendar.get(Calendar.MONTH) + 1);        setNpMinValAndMaxVal(dayNp, 1, getDaysInMonthAndYear(yearNp.getValue(), monthNp.getValue()));        dayNp.setValue(calendar.get(Calendar.DAY_OF_MONTH));    }    /**     * 根据具体的年月日展示日期     *     * @param year     * @param month     * @param day     */    public void setDisplayValue(int year, int month, int day) {        checkNumIsInRange(year, MIN_YEAR, MAX_YEAR, "请输入" + MIN_YEAR + "~~~~" + MAX_YEAR + "之间的年份");        yearNp.setValue(year);        checkNumIsInRange(month, MIN_MONTH, MAX_MONTH, "请输入" + MIN_MONTH + "~~~~" + MAX_MONTH + "之间的月份");        monthNp.setValue(month);        int maxDays = getDaysInMonthAndYear(yearNp.getValue(), monthNp.getValue());        setNpMinValAndMaxVal(dayNp, 1, maxDays);        checkNumIsInRange(day, 1, maxDays                , "请输入" + 1 + "到" + maxDays + "之间的天数");        dayNp.setValue(day);    }    /**     * 检查输入的数字是否在范围内     *     * @param checkNum     * @param minNum     * @param maxNum     * @param message     */    private void checkNumIsInRange(int checkNum, int minNum, int maxNum, String message) {        if (checkNum < minNum || checkNum > maxNum) {            throw new NumberFormatException(message);        }    }    /**     * 获取当前展示的日期 类型为Date     *     * @return 返回值为Date类型     */    public Date getDisplayDate() {        Calendar calendar = Calendar.getInstance();        calendar.set(yearNp.getValue(), monthNp.getValue() - 1, dayNp.getValue());        return calendar.getTime();    }    /**     * 获取指定格式的日期字符串     *     * @param pattern     * @return     */    public String getDisPlayDateStr(String pattern) {        Calendar calendar = Calendar.getInstance();        calendar.set(yearNp.getValue(), monthNp.getValue() - 1, dayNp.getValue());        Date date = calendar.getTime();        SimpleDateFormat simpleDateFormat = new SimpleDateFormat(pattern);        return simpleDateFormat.format(date);    }    /**     * 获取当前展示的年份     *     * @return 返回年份     */    public int getDisplayYear() {        return yearNp.getValue();    }    /**     * 获取当前展示的月份     *     * @return 返回月份     */    public int getDisplayMonth() {        return monthNp.getValue();    }    /**     * 返回当前展示的某一月的第几天     *     * @return 返回月份的第几天     */    public int getDisplayDay() {        return dayNp.getValue();    }    /**     * 设置NumberPicker的取值范围     *     * @param np     * @param minVal     * @param maxVal     */    private void setNpMinValAndMaxVal(NumberPicker np, int minVal, int maxVal) {        np.setMinValue(minVal);        np.setMaxValue(maxVal);    }}

xcy_date_picker.xml

<pre name="code" class="html"><?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="horizontal">    <NumberPicker        android:id="@+id/year_np"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_weight="1"></NumberPicker>    <NumberPicker        android:id="@+id/month_np"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_marginLeft="4dp"        android:layout_weight="1"></NumberPicker>    <NumberPicker        android:id="@+id/day_np"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_marginLeft="4dp"        android:layout_weight="1"></NumberPicker></LinearLayout>

直接粘贴代码了