思路：

1、获取当月第一天是周几

2、获取当月共几天

通过获取下月的第0天，即是当月最后一天日期

3、通过二维数组构造当月日历

4、将获取到的日期第一天在日历中展示..

知识点：

1、js获取当月的天数

getDate() 方法可返回月份的某一天，返回值是 1 ~ 31 之间的一个整数。

var d = new Date()

document.write(d.getDate())

输出：17

getDay() 方法可返回表示星期的某一天的数字，返回值是 0(周日) 到 6(周六) 之间的一个整数。

var d=new Date()

document.write(d.getDay())

输出：3

var d = new Date();

//d.getMonth()+1代表下个月，月份索引从0开始，即当前月为6月时，getMonth()返回值为5，创建日期时同理

//此处构造的日期为下个月的第0天，天数索引从1开始，第0天即代表上个月的最后一天

var curMonthDays = new Date(d.getFullYear(), (d.getMonth()+1), 0).getDate();

alert("本月共有 "+ curMonthDays +" 天");

2、构造当月日历二维数组

bulidCal : function(iYear, iMonth) {

var aMonth = new Array();

aMonth[0] = new Array(7);

aMonth[1] = new Array(7);

aMonth[2] = new Array(7);

aMonth[3] = new Array(7);

aMonth[4] = new Array(7);

aMonth[5] = new Array(7);

aMonth[6] = new Array(7);

var dCalDate = new Date(iYear, iMonth - 1, 1);

var iDayOfFirst = dCalDate.getDay();

var iDaysInMonth = calUtil.getDaysInmonth(iMonth, iYear);

var iVarDate = 1;

var d, w;

aMonth[0][0] = "日";

aMonth[0][1] = "一";

aMonth[0][2] = "二";

aMonth[0][3] = "三";

aMonth[0][4] = "四";

aMonth[0][5] = "五";

aMonth[0][6] = "六";

for (d = iDayOfFirst; d < 7; d++) {

aMonth[1][d] = iVarDate;

iVarDate++;

}

for (w = 2; w < 7; w++) {

for (d = 0; d < 7; d++) {

if (iVarDate <= iDaysInMonth) {

aMonth[w][d] = iVarDate;

iVarDate++;

}

}

}

return aMonth;

}

获取当月第一天是周几：

var dCalDate = new Date(iYear, iMonth - 1, 1);

var iDayOfFirst = dCalDate.getDay();

获取当月共几天：

getDaysInmonth : function(iMonth, iYear){

var dPrevDate = new Date(iYear, iMonth, 0);

return dPrevDate.getDate();

}

3、构造当月日历HTML

drawCal : function(iYear, iMonth ,signList) {

var myMonth = calUtil.bulidCal(iYear, iMonth);

var htmls = new Array();

htmls.push("

");

return htmls.join('');

}

4、控件的事件处理机制

指定一个默认的eventName:"load"，不同的事件定义不同的eventName

默认时：

setMonthAndDay:function(){

switch(calUtil.eventName)

{

case "load":

var current = new Date();

calUtil.showYear=current.getFullYear();

calUtil.showMonth=current.getMonth() + 1;

break;

case "prev":

var nowMonth=$(".calendar_month_span").html().split("年")[1].split("月")[0];

calUtil.showMonth=parseInt(nowMonth)-1;

if(calUtil.showMonth==0)

{

calUtil.showMonth=12;

calUtil.showYear-=1;

}

break;

case "next":

var nowMonth=$(".calendar_month_span").html().split("年")[1].split("月")[0];

calUtil.showMonth=parseInt(nowMonth)+1;

if(calUtil.showMonth==13)

{

calUtil.showMonth=1;

calUtil.showYear+=1;

}

break;

}

},

不同的事件触发：

bindEnvent:function(){

//绑定上个月事件

$(".calendar_month_prev").click(function(){

//ajax获取日历json数据

var signList=[{"signDay":"10"},{"signDay":"11"},{"signDay":"12"},{"signDay":"13"}];

calUtil.eventName="prev";

calUtil.init(signList);

});

//绑定下个月事件

$(".calendar_month_next").click(function(){

//ajax获取日历json数据

var signList=[{"signDay":"10"},{"signDay":"11"},{"signDay":"12"},{"signDay":"13"}];

calUtil.eventName="next";

calUtil.init(signList);

});

}

效果图:

页面引用：

签到效果实现

$(function(){

//ajax获取日历json数据

var signList=[{"signDay":"09"},{"signDay":"11"},{"signDay":"12"},{"signDay":"13"}];

calUtil.init(signList);

});

JS：

var calUtil = {

//当前日历显示的年份

showYear:2015,

//当前日历显示的月份

showMonth:1,

//当前日历显示的天数

showDays:1,

eventName:"load",

//初始化日历

init:function(signList){

calUtil.setMonthAndDay();

calUtil.draw(signList);

calUtil.bindEnvent();

},

draw:function(signList){

//绑定日历

var str = calUtil.drawCal(calUtil.showYear,calUtil.showMonth,signList);

$("#calendar").html(str);

//绑定日历表头

var calendarName=calUtil.showYear+"年"+calUtil.showMonth+"月";

$(".calendar_month_span").html(calendarName);

},

//绑定事件

bindEnvent:function(){

//绑定上个月事件

$(".calendar_month_prev").click(function(){

//ajax获取日历json数据

var signList=[{"signDay":"10"},{"signDay":"11"},{"signDay":"12"},{"signDay":"13"}];

calUtil.eventName="prev";

calUtil.init(signList);

});

//绑定下个月事件

$(".calendar_month_next").click(function(){

//ajax获取日历json数据

var signList=[{"signDay":"10"},{"signDay":"11"},{"signDay":"12"},{"signDay":"13"}];

calUtil.eventName="next";

calUtil.init(signList);

});

},

//获取当前选择的年月

setMonthAndDay:function(){

switch(calUtil.eventName)

{

case "load":

var current = new Date();

calUtil.showYear=current.getFullYear();

calUtil.showMonth=current.getMonth() + 1;

break;

case "prev":

var nowMonth=$(".calendar_month_span").html().split("年")[1].split("月")[0];

calUtil.showMonth=parseInt(nowMonth)-1;

if(calUtil.showMonth==0)

{

calUtil.showMonth=12;

calUtil.showYear-=1;

}

break;

case "next":

var nowMonth=$(".calendar_month_span").html().split("年")[1].split("月")[0];

calUtil.showMonth=parseInt(nowMonth)+1;

if(calUtil.showMonth==13)

{

calUtil.showMonth=1;

calUtil.showYear+=1;

}

break;

}

},

getDaysInmonth : function(iMonth, iYear){

var dPrevDate = new Date(iYear, iMonth, 0);

return dPrevDate.getDate();

},

bulidCal : function(iYear, iMonth) {

var aMonth = new Array();

aMonth[0] = new Array(7);

aMonth[1] = new Array(7);

aMonth[2] = new Array(7);

aMonth[3] = new Array(7);

aMonth[4] = new Array(7);

aMonth[5] = new Array(7);

aMonth[6] = new Array(7);

var dCalDate = new Date(iYear, iMonth - 1, 1);

var iDayOfFirst = dCalDate.getDay();

var iDaysInMonth = calUtil.getDaysInmonth(iMonth, iYear);

var iVarDate = 1;

var d, w;

aMonth[0][0] = "日";

aMonth[0][1] = "一";

aMonth[0][2] = "二";

aMonth[0][3] = "三";

aMonth[0][4] = "四";

aMonth[0][5] = "五";

aMonth[0][6] = "六";

for (d = iDayOfFirst; d < 7; d++) {

aMonth[1][d] = iVarDate;

iVarDate++;

}

for (w = 2; w < 7; w++) {

for (d = 0; d < 7; d++) {

if (iVarDate <= iDaysInMonth) {

aMonth[w][d] = iVarDate;

iVarDate++;

}

}

}

return aMonth;

},

ifHasSigned : function(signList,day){

var signed = false;

$.each(signList,function(index,item){

if(item.signDay == day) {

signed = true;

return false;

}

});

return signed ;

},

drawCal : function(iYear, iMonth ,signList) {

var myMonth = calUtil.bulidCal(iYear, iMonth);

var htmls = new Array();

htmls.push("

");

return htmls.join('');

}

};