问题
I am just testing the brand new Internet Explorer 9 Beta with my website. I see a weird behaviour for some form values and I am not sure if it is my mistake or a bug in IE9. What do you think?
I have one form which declares several hidden input fields like this
<input type="hidden" name="NewStatus" />
<input type="hidden" name="lastSaveStatus" value="" />
When the page is being submitted, the values are saved like this (in JavaScript):
newStatus.setAttribute("value", myNewStatus);
var formLastStatus = document.getElementsByName("lastSaveStatus")[0];
formLastStatus.setAttribute("value", lastSaveStatus);
alert(lastSaveStatus);
alert(formLastStatus.getAttribute("value"));
var form = document.getElementById("myForm");
form.submit();
That code has worked for years and across all browsers. The alerts already indicate that I have now a problem with the lastSaveStatus field. In IE9 the NewStatus is correctly transmitted to the server (means that I can access the value in ASP.NET using Request.Form["NewStatus"]). But the value for "lastSaveStatus" is always "".
As you can see I used a value="" in the definition of my hidden field. If I remove this default value, the new value is correctly transferred to the server. If I use a default value, always the default value is transferred.
Any idea why this is happening?
回答1:
Are you sure this worked in previous versions of IE? I've always had problems with that syntax in IE/Win, the following should work however:
formLastStatus.value = lastSaveStatus;
The above should work in all browsers, too.
来源：https://stackoverflow.com/questions/3724207/html-form-default-values-override-actual-values-at-post-time-in-internet-explore