检测隐藏的表单字段何时动态更改

Question

我们如何检测隐藏的表单字段何时动态更改？如果已更改，则显示警告？

JQuery UI（DatePicker）用于更改隐藏的表单字段。

$("#datepicker").datepicker({altField: "#alternate", altFormat: "yymmdd"}).$('#alternate').trigger('change');


<input name="textbox" id="alternate" type="hidden" size="30" 
onchange="alert('changed')" />

Answer 1

$('#alternate').change(function(){
    window.alert('Change has happened.  Ya dig?');
});

Answer 2

在StackOverflow.com上的两个类似问题的帮助下解决了这个问题

1. jQuery UI datepicker - Trying to capture click event from date clicked
2. jQuery - Detect value change on hidden input field

---

<input name="textbox" id="alternate" type="hidden" size="30" 
onchange="alert('changed')" />


<script>
$(function() {
    $("#myDatePicker").datepicker({
        // The hidden field to receive the date
        altField: "#alternate",
        // The format for the date
        altFormat: "yymmdd",
        onSelect: function (date) {
            // trigger the .change() event
            $('#alternate').trigger('change');
        }
    })
});
</script>