根据年份选择周数-js

选择周数的css用的是bootstrap，百度后最终整理如下：

效果：

HTML代码如下：

                <div class="btn-group">
                    <button type="button" class="my my1 btn btn-primary dropdown-toggle ft18" data-toggle="dropdown" style=" 120px;">
                        <span></span>&nbsp;&nbsp;
                        <span class="yearText priceData">选择年份</span>&nbsp;&nbsp;
                    </button>
                    <ul class="my line20 dropdown-menu ft16" role="menu" id="priceDataYear">
                    </ul>
                </div>
                <div class="btn-group">
                <button type="button" class="my my1 btn btn-primary dropdown-toggle ft18" data-toggle="dropdown" style=" 250px;">
                <span></span>&nbsp;&nbsp;
                <span class="weekText priceData">选择周数</span>&nbsp;&nbsp;
                <span class="caret"></span>
                </button>
                    <ul class="my line20 dropdown-menu ft16" role="menu" id="priceDataWeek">
                    </ul>
                </div>
               </div>

js代码如下：

<script type="text/javascript">
    $(function(){
        showYear();
    });
//    显示近5年
    function showYear() {
    var nowDate = new Date();
    //设置近5年的年份
    var nowYear = nowDate.getFullYear();
    var yearHtml = '<li><a href="javaScript:void(0)" onclick="year($(this).text())">选择年份</a></li>';
    for (var i = 0; i < 5; i++) {
        yearHtml += '<li><a href="javaScript:void(0)" onclick="year($(this).text())">' + (nowYear - i) + '年</a></li>';
    }
    $('#priceDataYear').html(yearHtml);
    }
    
    function year(text) {
        $('.yearText.priceData').text(text);
        $('.weekText').text('选择周数');
        var weekHtml = '';
        if(text != '选择年份') {
            var year = parseInt(text.substring(0, text.length - 1));
            //计算出这年的周数
            var weekNum = getNumOfWeeks(year);
            //首先算出这年的第一个星期日
            var firstSunday = new Date(year, 0, 1);
            var n = 6 - (firstSunday.getDay() + 6) % 7;
            firstSunday.setDate(firstSunday.getDate() + n);
            //根据年份设置周数
            weekHtml += '<li><a href="javaScript:void(0)" onclick="week($(this).text())">选择周数</a></li>';
            for(var i = 1; i <= weekNum; i++) {
                if(i == 1) {
                    //计算这年第一个周一的日期
                    var firstMonday = new Date(firstSunday.setDate(firstSunday.getDate() - 6));
                    firstSunday.setDate(firstSunday.getDate() + 6);
                    weekHtml += '<li><a href="javaScript:void(0)" onclick="week($(this).text())">第' + i + '周（' + getNowFormatDate(firstMonday) + '）-（' + getNowFormatDate(firstSunday) + '）</a></li>';
                } else {
                    weekHtml += '<li><a href="javaScript:void(0)" onclick="week($(this).text())">第' + i + '周' + getDateRange(firstSunday) + '</a></li>';
                    //计算出下一个星期日，有个问题是上面调用getDateRange()已经firstSunday加了7天，这里就不需要重新firstSunday加7天
                    // firstSunday.setDate(firstSunday.getDate() + 7);
                }
            }
        }
        $('#priceDataWeek').html(weekHtml);
    }
    function week(wk){
        $('.weekText.priceData').text(wk);
    }
    function getNumOfWeeks(year) {
    //设置为这一年开始日期
    var startDateOfYear = new Date(year, 0, 1);
    //计算这一年有多少天
    var daysOfYear = ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) ? 366 : 365;
    //366（365）/7=52.2(52.1)，所以一般一年有52周余1天或者2天，当这一年有366天时且第一天是周日，那么他的最后一天则是周一，这一年就有54周。
    var weekNum = 53;
    //当年份是闰年且第一天是周日时有54周
    if (startDateOfYear.getDay() == 0 && daysOfYear == 366) {
        weekNum = 54;
    }
    return weekNum;
    }
        /**
     * 根据上周日获取这周日的日期范围
     * @param lastSunday
     * @returns
     */
    function getDateRange(lastSunday) {
        if (lastSunday == null || lastSunday == '') {
            return "";
        }
        var beginDate = new Date(lastSunday.setDate(lastSunday.getDate() + 1));
        var endDate = new Date(lastSunday.setDate(lastSunday.getDate() + 6));
        return '（' + getNowFormatDate(beginDate) + '）-' + '（' + getNowFormatDate(endDate) + '）';
    }
    
    /**
     * 时间转换成字符串
     * @param date
     * @returns
     */
    function getNowFormatDate(date) {
        var Month = 0;
        var Day = 0;
        var CurrentStr = "";
        // 初始化时间
        Month = date.getMonth() + 1;
        Day = date.getDate();
        if (Month >= 10) {
            CurrentStr += Month + "月";
        } else {
            CurrentStr += "0" + Month + "月";
        }
        if (Day >= 10) {
            CurrentStr += Day + "日";
        } else {
            CurrentStr += "0" + Day + "日";
        }
        return CurrentStr;
    }
</script>