--- theme: geek-black highlight: androidstudio --- ### 效果预览 ![image](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/0b78dbca797747539013534d24f663ba~tplv-k3u1fbpfcp-zoom-1.image) ### 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 ```java 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 ```java private ArrayList 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 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 ```java private ArrayList 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 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下载地址](https://github.com/cenxiaoping/CustomCalendarView)