js 日历控件

效果

可以切换月份

	//初始化当月
	initDate:function(){
		let that =this;
        let currentDate=new Date();
        let year=currentDate.getFullYear();
        let month = currentDate.getMonth()+1;
        $('#yearTxt').text(year+'年'+(month)+'月');
        let monthFirst=year+'-'+(month)+'-'+'1';
        this.getDateShow(monthFirst,month);
        
		//点击上一月
        $(document).on('click','[f="up_month"]',function(){
            let upDate='';
            //如果是1月
            if(month==1){
                year=year-1;
                month=12;
                upDate=year+'-'+month+'-1';
            }else{
                //上一月 月份-1
                month= month-1;
                upDate=year+'-'+(month)+'-1';
            }
            that.getDateShow(upDate,month);
            $('#yearTxt').text(year+'年'+(month)+'月');
        })

        //点击下一月
        $(document).on('click','[f="next_month"]',function(){
            let nextDate='';
            //如果是12月
            if(month==12){
                year=year+1;
                month=1;
                nextDate=year+'-'+month+'-1';
            }else{
                //下一月月份+1
                month= month+1;
                nextDate=year+'-'+(month)+'-1';
            }
            that.getDateShow(nextDate,month);
            $('#yearTxt').text(year+'年'+(month)+'月');
        })
    },
    //渲染计算，monthFirst月第一天的日期，month月
    getDateShow:function(monthFirst,month){
        let dayTime = 1000*60*60*24;//一天的毫秒数
        let dayLengt=42;//表格需要展示的天数
        let monthFirstTime=new Date(monthFirst).getTime();//本月第一天时间戳
        let firstWeek=new Date(monthFirst).getDay();//获取当月第一天星期几
        if(firstWeek==0){   //星期数为0等于星期天
            firstWeek=7;
        }
         //使用当月第一天减去星期数获取第一天开始日期
         let firstDay=new Date(monthFirstTime - ((firstWeek-1)*dayTime)).getTime();

         //获取最后一个日期
         let lastDay=new Date(firstDay+(dayLengt*dayTime)).getTime();
         let showDate='';
         for(let i= firstDay; i< lastDay; i+=dayTime){
             let showCurrnetDate=new Date(i);
             console.log(showCurrnetDate.getFullYear()+'年'+showCurrnetDate.getMonth()+'月'+showCurrnetDate.getDate()+'日');
             if(showCurrnetDate.getMonth()+1 != month){ //不是本月颜色为灰色
                 showDate+=`${showCurrnetDate.getDate()}`
             }else{
                 showDate+=`${showCurrnetDate.getDate()}`
             }
         }
         $('#daylist').html(showDate);
    },