所使用到的JavaScript代码如下:
将以上代码在页面中引用:
var i = 0;
function addAttachmentToList(){
if (findAttachment(event.srcElement.value)) return;
var span = document.createElement('span');
span.id = '_attachment' + i;
span.innerHTML = extractFileName(event.srcElement.value) + ' <a href="javascript:delAttachment(' + (i++) + ')"><font color="blue">删除</font></a><br/>';
span.title = event.srcElement.value;
G('attachmentList').appendChild(span);
if (G('attachmentList').style.display == 'none')
{
G('btnAdd').value = '继续添加';
G('attachmentList').style.display = '';
G('btnClear').style.display = '';
}
G('total').innerText = '当前选择上传'+ G('attachmentList').childNodes.length + '个附件';
}
function selectAttachment()
{
cleanInvalidUpfile();
var upfile = '<input type="file" style="display:none" onchange="addAttachmentToList();" id="_upfile'+i+'">';
document.body.insertAdjacentHTML('beforeEnd', upfile);
G('_upfile'+i).click();
}
function extractFileName(fn)
{
return fn.substr(fn.lastIndexOf("\\") + 1);
}
function findAttachment(fn)
{
var o = G('attachmentList').getElementsByTagName('span');
for(var i=0;i<o.length;i++)
if (o[i].title == fn) return true;
return false;
}
function delAttachment(id)
{
G('attachmentList').removeChild(G('_attachment'+id));
document.body.removeChild(G('_upfile'+id));
// 当附件列表为空则不显示并且变化添加附件按钮文本
if (G('attachmentList').childNodes.length == 0)
{
G('btnAdd').value = '添加附件';
G('attachmentList').style.display = 'none';
G('btnClear').style.display = 'none';
}
G('total').innerText = '当前选择上传'+ G('attachmentList').childNodes.length + '个附件';
}
function cleanInvalidUpfile()
{
var o = document.body.getElementsByTagName('input');
for(var i=o.length-1;i>=0;i--)
if (o[i].type == 'file' && o[i].id.indexOf('_upfile') == 0)
{
if (!G('_attachment'+o[i].id.substr(7)))
document.body.removeChild(o[i]);
}
}
function clearAttachment()
{
var o = G('attachmentList').childNodes;
for(var i=o.length-1;i>=0;i--)
G('attachmentList').removeChild(o[i]);
o = document.body.getElementsByTagName('input');
for(var i=o.length-1;i>=0;i--)
if (o[i].type == 'file' && o[i].id.indexOf('_upfile') == 0)
{
document.body.removeChild(o[i]);
}
G('btnAdd').value = '添加附件';
G('attachmentList').style.display = 'none';
G('btnClear').style.display = 'none';
G('total').innerText = '当前选择上传0个附件';
}
function G(id)
{
return document.getElementById(id);
}
将以上代码在页面中引用:
<HTML>
<HEAD></HEAD>
<BODY>
<fieldset style="border : 1px solid #84A24A;text-align:left;COLOR:#84A24A;FONT-SIZE:
12px;font-family: Verdana;padding:5px;">
<legend>模仿126 GMail QQ邮箱添加附件</legend>
<input type="button" value="添加附件" id="btnAdd" onclick="selectAttachment();"> <input type="button" value="清空附件" id="btnClear" style="display:none" onclick="clearAttachment();">
<div id="attachmentList" style="margin:3px 0px 0px 0px;padding:4px 3px 4px 3px;background-color:#DEEBC6;display:none;border:1px solid #84A24A;">
</div>
<div id="total" style="margin:3px 0px 0px 0px;">当前选择上传0个附件</div>
</fieldset>
</BODY>
</HTML>