我有一个表单上传图像.我想禁用提交按钮,直到用户选择要上传的图像.我想用jQuery做.目前,我有一个JavaScript,阻止用户在提交表单时多次提交表单.将这个功能与新的功能结合起来真是太好了.
这是我现在所做的：
<script type="text/javascript">
function submitonce(theform) {
//if IE 4+ or NS 6+
if (document.all || document.getElementById) {
//screen thru every element in the form,and hunt down "submit" and "reset"
for (i = 0; i < theform.length; i++) {
var tempobj = theform.elements[i]
if (tempobj.type.toLowerCase() == "submit" || tempobj.type.toLowerCase() == "reset")
//disable em
tempobj.disabled = true
}
}
}
</script>
<form name="form" enctype="multipart/form-data" method="post" action="upload.PHP" onSubmit="submitonce(this)">
<input type="file" name="my_field" value="" />
<input type="submit">
</form>
解决方法
以下内容似乎在Chrome和Firefox(Ubuntu 10.10)中可靠运行,目前我无法查看其他平台：
jQuery的
$(document).ready(
function(){
$('input:file').change(
function(){
if ($(this).val()) {
$('input:submit').attr('disabled',false);
// or,as has been pointed out elsewhere:
// $('input:submit').removeAttr('disabled');
}
}
);
});
HTML
<form action="#" method="post">
<input type="file" name="fileInput" id="fileInput" />
<input type="submit" value="submit" disabled />
</form>
<div id="result"></div>
