Javascript 从级联选择元素更改事件调用外部JS函数

我是这里的jquerynoob，我正在尝试找出如何将这个脚本移动到外部的.js文件中。我已经尝试过复制它并在页面上引用它，但它似乎不起作用

我错过了什么

<script type="text/javascript">
$(document).ready(function () {
    $('#YearD').change(function () {
        var selectedYear = $(this).val();
        if (selectedYear != null && selectedYear != '') {
            $.getJSON('@Url.Action("Months")', { year: selectedYear }, function (months) {
                var monthsSelect = $('#Month');
                monthsSelect.empty();
                $.each(months, function (index, month) {
                    monthsSelect.append($('<option/>', {
                        value: month.value,
                        text: month.text
                    }));
                });
            });
        }
    });
});
</script>

<script type="text/javascript">
$('#Month').change(function () {
    var selectedMonth = $(this).val();
    if (selectedMonth != null && selectedMonth != '') {
        $.getJSON('@Url.Action("Days")', { month: selectedMonth }, function (days) {
            var daysSelect = $('#Day');
            daysSelect.empty();
            if (days == 0) {
                daysSelect.css("visibility", "hidden");
            }
            else {
                daysSelect.css("visibility", "visible");
            }
            $.each(days, function (index, day) {
                daysSelect.append($('<option/>', {
                    value: day.value,
                    text: day.text
                }));
            });
        });
    }
});
</script>

---

将以下内容添加到要运行代码的页面：

<script src="js_file_name.js"></script>

然后将代码直接复制并粘贴到名为js_file_name.js的文件中，然后从外部文件中删除

将此添加到HTML文件：

<script type="text/javascript" src="filename.js"></script>

如果有,

<script type="text/javascript">
$(document).ready(function () {
   // your code
})

请注意，myfile.js文件中没有标记

另外，请记住您的代码使用的是jQuery，所以请在引用jQuery.js文件之后再引用myfile.js

e、 g

<script type='text/javascript' src='scripts/myfile.js'></script>

$(document).ready(function () {
   // your code
})

<script type='text/javascript' src='scripts/myfile.js'></script>
<script type='text/javascript' src='http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js'></script>

$(document).ready(function () {
    $('#YearD').change(function () {
        var selectedYear = $(this).val();
        if (selectedYear != null && selectedYear != '') {
            $.getJSON('@Url.Action("Months")', { year: selectedYear }, function (months) {
                var monthsSelect = $('#Month');
                monthsSelect.empty();
                $.each(months, function (index, month) {
                    monthsSelect.append($('<option/>', {
                        value: month.value,
                        text: month.text
                    }));
                });
            });
        }
    });
    $('#Month').change(function () {
    var selectedMonth = $(this).val();
    if (selectedMonth != null && selectedMonth != '') {
        $.getJSON('@Url.Action("Days")', { month: selectedMonth }, function (days) {
            var daysSelect = $('#Day');
            daysSelect.empty();
            if (days == 0) {
                daysSelect.css("visibility", "hidden");
            }
            else {
                daysSelect.css("visibility", "visible");
            }
            $.each(days, function (index, day) {
                daysSelect.append($('<option/>', {
                    value: day.value,
                    text: day.text
                }));
            });
        });
        }
    });

});