一起学写js Calender日历控件

最近看了一下关于js日期的一些函数，突然想到了日历控件，于是试着写了一个，作为后台程序员的我水平有限，大家抱着学习的态度看看我写的这个例子吧，一起学习进步！

首先一个常用的日期函数：

Date(year,month,day)

var   date=new  Date();

获取年份

var   year=this.date.getFullYear();

获取月份，这里是月索引所以要+1

var   month=this.date.getMonth()+1;

获取当天是几号

var   day=this.date.getDate();

获取当天是周几，返回0.周日   1.周一  2.周二  3.周三  4.周四  5.周五  6.周六

var   week=this.date.getDay();

 获取当月一号是周几

 var   getWeekDay=function(year,month,day){
      var date=new Date(year,month,day);
      return date.getDay();
      }

　　　var  weekstart= getWeekDay(this.year, this.month-1, 1)

获取当月的天数

var getMonthDays=function(year,month){
      var date=new Date(year,month,0);
      return date.getDate();
    }
var  monthdays= this.getMonthDays(this.year,this.month);

好了，我们用到的参数就这么多，后面其实就是关于日期对应周几的一些操作和判断，动态的拼接标签，下面就直接把我写的例子发出来：

效果图：

<html>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<head>
  <style type="text/css">

td{ text-align: center;}
  </style>
  <script type="text/javascript">

window.onload=function(){
  var  Calender=function(){
    this.Init.apply(this,arguments);
  }
  Calender.prototype={
    Init:function(container,options){
      this.date=new Date();
      this.year=this.date.getFullYear();
      this.month=this.date.getMonth()+1;
      this.day=this.date.getDate();
      this.week=this.date.getDay();
      this.weekstart=this.getWeekDay(this.year, this.month-1, 1);
      this.monthdays= this.getMonthDays(this.year,this.month);
      this.containerDiv=document.getElementById(container);
      this.options=options!=null?options:{
        border:'1px solid green',
        width:'400px',
        height:'200px',
        backgroundColor:'lightgrey',
        fontColor:'blue'
      }
    },
    getMonthDays:function(year,month){
      var date=new Date(year,month,0);
      return date.getDate();
    },
    getWeekDay:function(year,month,day){
      var date=new Date(year,month,day);
      return date.getDay();
    },
    View:function(){
      var tablestr='<table>';
       tablestr+='<tr><td colspan="3"></td><td>年:'+this.year+'</td><td colspan="3">月：'+this.month+'</td></tr>';
      tablestr+='<tr><td width="14%">日</td><td width="14%">一</td><td width="14%">二</td><td width="14%">三</td><td width="14%">四</td><td width="14%">五</td><td width="14%">六</td></tr>';
      var index=1;
      //判断每月的第一天在哪个位置
      var style='';
      if(this.weekstart<7)
      {
        tablestr+='<tr>';
         for (var i = 0; i <this.weekstart; i++) {
           tablestr+='<td></td>';
         };
         for (var i = 0; i < 7-this.weekstart; i++) {
          style=this.day==(i+1)?"background-Color:green;":"";
           index++;
           tablestr+='<td style="'+style+'" val='+(this.year+'-'+this.month+'-'+(i+1))+'>'+(i+1)+'</td>';
         };
        tablestr+='</tr>';

      }
      ///剩余天数对应的位置

      //判断整数行并且对应相应的位置
      var remaindays=this.monthdays-(7-this.weekstart);
      var row=Math.floor(remaindays%7==0?remaindays/7:((remaindays/7)+1)) ;
      var  count=Math.floor(remaindays/7);
      for (var i = 0; i < count; i++) {
         tablestr+='<tr>';
         for (var k = 0; k < 7; k++) {
           style=this.day==(index+k)?"background-Color:green;":"";
           tablestr+='<td style="'+style+'" val='+(this.year+'-'+this.month+'-'+(index+k))+'>';
           tablestr+=index+k;
           tablestr+='</td>';
         };
         tablestr+='</tr>';
         index+=7;
      };

      //最后剩余的天数对应的位置(不能填充一周的那几天)
      var remaincols=this.monthdays-(index-1);
      tablestr+='<tr>';
      for (var i = 0; i < remaincols; i++) {
        style=this.day==index?"background-Color:green;":"";
        tablestr+='<td style="'+style+'" val='+(this.year+'-'+this.month+'-'+(index))+'>';
        tablestr+=index;
        tablestr+='</td>';
        index++;
      };
      tablestr+='</tr>';
      tablestr+='</table>';
      return tablestr;
    },
    Render:function(){
      var calenderDiv=document.createElement('div');
      calenderDiv.style.border=this.options.border;
      calenderDiv.style.width=this.options.width;
      calenderDiv.style.height=this.options.height;
      calenderDiv.style.cursor='pointer';
      calenderDiv.style.backgroundColor=this.options.backgroundColor;
      // calenderDiv.style.color=this.options.fontColor;
      calenderDiv.style.color='red' ;

      calenderDiv.onclick=function(e){
        var evt=e||window.event;
        var  target=evt.srcElement||evt.target;

        if(target&&target.getAttribute('val'))
        {

          alert(target.getAttribute('val'));
        }

      }
      var tablestr=this.View();
      this.tablestr=tablestr;
      calenderDiv.innerHTML=tablestr;
      var div=document.createElement('div');
      div.style.width='auto';
      div.style.height='auto';
       div.appendChild(calenderDiv);

       ///翻页div
      var pagerDiv=document.createElement('div');
      pagerDiv.style.width='auto';
      pagerDiv.style.height='auto';

        var that=this;

        ///重新设置参数
      var  resetPara=function(year,month,day){
          that.date=new Date(year,month,day);
          that.year=that.date.getFullYear();
          that.month=that.date.getMonth()+1;
          that.day=that.date.getDate();
          that.week=that.date.getDay();
          that.weekstart=that.getWeekDay(that.year, that.month-1, 1);
          that.monthdays= that.getMonthDays(that.year,that.month);
      }

      //上一页
      var preBtn=document.createElement('input');
       preBtn.type='button';
       preBtn.value='<';

       preBtn.onclick=function(){
           that.containerDiv.removeChild(div);
           resetPara(that.year,that.month-2,that.day);
           that.Render();

       }
       //下一页
       var nextBtn=document.createElement('input');
       nextBtn.type='button';
       nextBtn.value='>';

       nextBtn.onclick=function(){
           that.containerDiv.removeChild(div);
           resetPara(that.year,that.month,that.day);
           that.Render();

       }

       pagerDiv.appendChild(preBtn);
       pagerDiv.appendChild(nextBtn);
       div.appendChild(pagerDiv);

       var dropDiv=document.createElement('div');
       var  dropdivstr='';
       //选择年份
       dropdivstr+='<select id="ddlYear">';
       for (var i = 1900; i <= 2100; i++) {
        dropdivstr+=
        i==that.year
        ?'<option value="'+i+'" selected="true">'+i+'</option>'
        : '<option value="'+i+'">'+i+'</option>';
       };
       dropdivstr+='</select>';

      //选择月份
      dropdivstr+='<select id="ddlMonth">';
       for (var i = 1; i <= 12; i++) {
        dropdivstr+=
        i==that.month
        ?'<option value="'+i+'" selected="true">'+i+'</option>'
        : '<option value="'+i+'">'+i+'</option>';
       };
       dropdivstr+='</select>';
       dropDiv.innerHTML=dropdivstr;
       div.appendChild(dropDiv);
      that.containerDiv.appendChild(div);

       ///绑定选择年份和月份的事件
       var ddlChange=function(){
           var ddlYear=document.getElementById('ddlYear');
          var ddlMonth=document.getElementById('ddlMonth');
          var  yearIndex=ddlYear.selectedIndex;
          var year=ddlYear.options[yearIndex].value;
          var  monthIndex=ddlMonth.selectedIndex;
          var month=ddlMonth.options[monthIndex].value;
          that.containerDiv.removeChild(div);
          resetPara(year,month-1,that.day);
          that.Render();
       }

      ddlYear.onchange=function(){
         ddlChange();
      }

       ddlMonth.onchange=function(){
         ddlChange();

      }
    }

  }

  var  calender=new Calender('dvTest',{
        border:'1px solid green',
        width:'400px',
        height:'200px',
        backgroundColor:''
        }
        );
  calender.Render();

}
  </script>

</head>
<body>
 <div id="dvTest"></div>
</body>
</html>

代码重新做了改动，将视图的table换为了div,是为了解决IE的tableinnerHTML的只读问题。另外加了options是为了可配置性。
上面代码有简单说明，功能是最基础的，如果更深入的做可以进行扩展，希望这篇文章可以给大家一些启发。