Android Calendar自定义日历控件

效果预览

思路：

1、RecyclerView+Calendar
2、Calendar获取整月的天数
3、Calendar获取上一个月和下一个月需要补全的天数

1、Calendar获取整月的天数

 Calendar instance = Calendar.getInstance();

        if (indexDate != null) {
            //自定月份
            instance.setTime(indexDate.getDate());
        }

        //获取当前月最大的日期
        int maxDate = instance.getActualMaximum(Calendar.DATE);
        instance.set(Calendar.DAY_OF_MONTH, 1);
        //获取当前月所有的天数
        for (int i = 0; i < maxDate; i++, instance.add(Calendar.DATE, 1)) {
            int day = instance.get(Calendar.DAY_OF_MONTH);
            CalendarBean calendarBean = new CalendarBean();
            calendarBean.setDay(String.valueOf(day));
            calendarBean.setDate(instance.getTime());
            mDatas.add(calendarBean);
        }

2、获取上一个月需要补全的天数

 private ArrayList<CalendarBean> getLastMonth(CalendarBean calendarBean) {
        //获取当前月第一天
        Calendar calendarFirstDay = Calendar.getInstance();
        calendarFirstDay.setTime(calendarBean.getDate());
        calendarFirstDay.set(Calendar.DAY_OF_MONTH, 1);
        //当月第一天是星期几
        int firstDayOfWeek = calendarFirstDay.get(Calendar.DAY_OF_WEEK);
        if (firstDayOfWeek != 1) {
            /**
             *   firstDayOfWeek =1时，就是星期日，当前月第一天已经处于星期日，不需要添加上一个月补充天数
             */
            //需要补全的天数，当needAdd为负数时候，说明是星期日，需要补6天
            int needAdd = firstDayOfWeek - 1;

            ArrayList<CalendarBean> lastMonth = new ArrayList<>();
            for (int i = 0; i < needAdd; i++) {
                CalendarBean dayBean = new CalendarBean();
                //0：当月，1：上月，2：下一个月
                dayBean.setDayType(1);
                dayBean.setWeekOfDay(getWeekString(i));
                //取出上一个月需要补全的天数
                //calendarFirstDay.set(Calendar.DAY_OF_MONTH, 0 - i);
                calendarFirstDay.add(Calendar.DATE, -1);
                //上一个月的天数
                int lastMonthDay = calendarFirstDay.get(Calendar.DAY_OF_MONTH);
                dayBean.setDay(String.valueOf(lastMonthDay));
                dayBean.setDate(dayBean.getDate());
                lastMonth.add(0, dayBean);
            }

            return lastMonth;

        }
        return new ArrayList<>();
    }

3、获取下一个月需要补全的天数

 private ArrayList<CalendarBean> getNextMonth(CalendarBean calendarBean) {

        //获取当前月最后一天
        Calendar calendarLastDay = Calendar.getInstance();
        calendarLastDay.setTime(calendarBean.getDate());
        calendarLastDay.add(Calendar.MONTH, 1);
        calendarLastDay.set(Calendar.DAY_OF_MONTH, 0);
        //获取当前月最后一天是星期几
        int nextDayOfWeek = calendarLastDay.get(Calendar.DAY_OF_WEEK);
        if (nextDayOfWeek != 7) {
            /**
             *   nextDayOfWeek =7时，就是星期六，当前月最后一天已经处于星期六，不需要添加上一个月补充天数
             */
            int needAdd = 7 - nextDayOfWeek;

            ArrayList<CalendarBean> nextMonth = new ArrayList<>();
            for (int i = 1; i <= needAdd; i++) {
                CalendarBean dayBean = new CalendarBean();
                //0：当月，1：上月，2：下一个月
                dayBean.setDayType(2);
                dayBean.setWeekOfDay(getWeekString(i));
                //取出上一个月需要补全的天数
                calendarLastDay.set(Calendar.DAY_OF_MONTH, i);
                //上一个月的天数
                int lastMonthDay = calendarLastDay.get(Calendar.DAY_OF_MONTH);
                dayBean.setDay(String.valueOf(lastMonthDay));
                dayBean.setDate(dayBean.getDate());
                nextMonth.add(dayBean);
            }
            return nextMonth;
        }
        return new ArrayList<>();
    }

Demo地址