jQuery:年月日三级联动

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default3.aspx.cs" Inherits="Default3" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <script src="js/jquery-1.7.2.min.js"></script>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:DropDownList ID="dr_year" runat="server"></asp:DropDownList><asp:DropDownList ID="dr_month" runat="server"></asp:DropDownList><asp:DropDownList ID="dr_day" runat="server"></asp:DropDownList></div>
    </form>
</body>
</html>
<script>
    var days = 0;
    years();
    months();
    Days();
    var date = new Date();
    $("#dr_year").val(date.getFullYear());
    $("#dr_month").val((date.getMonth() + 1));
    $("#dr_day").val(date.getDate());
    $("#dr_year").change(function () {
        months();
        Days();
    });

    $("#dr_month").change(function () {
        Days();
    });
    function years()
    {
        for(var i=1900;i<=2100;i++)
        {
            var str = "<option value="" + i + "">" + i+ "</option>";
            $("#dr_year").append(str);
        }
    }
    function months() {
        $("#dr_month").empty();
        for (var i = 1; i <= 12; i++) {
            var str = "<option value="" + i + "">" + i + "</option>";
            $("#dr_month").append(str);
        }
    }
    function Days() {
        $("#dr_day").empty();
        if (parseInt($("#dr_month").val()) == 1 || parseInt($("#dr_month").val()) == 3 || parseInt($("#dr_month").val()) == 5 || parseInt($("#dr_month").val()) == 7 || parseInt($("#dr_month").val()) == 8 || parseInt($("#dr_month").val()) == 10 || parseInt($("#dr_month").val()) == 12) {
            days = 31;
        }
        else if (parseInt($("#dr_month").val()) == 4 || parseInt($("#dr_month").val()) == 6 || parseInt($("#dr_month").val()) == 9 || parseInt($("#dr_month").val()) == 11) {
            days = 30;
        }
        else {
            if (parseInt($("#dr_year").val()) % 400 == 0 || (parseInt($("#dr_year").val()) % 4 == 0 && parseInt($("#dr_year").val()) % 100 != 0)) {
                days = 29;
            }
            else {
                days = 28;
            }
        }
        for (var i = 1; i <= days; i++) {
            var str = "<option value="" + i + "">" + i + "</option>";
            $("#dr_day").append(str);
        }
    }
</script>
原文地址:https://www.cnblogs.com/1711643472qq/p/6179644.html