<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
#preview_wrapper
{
display: inline-block;
width: 740px;
height: 200px;
background-color: #CCC;
}
#preview_fake
{
/* 该对象用户在IE下显示预览图片 */
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale);
}
#preview_size_fake
{
/* 该对象只用来在IE下获得图片的原始尺寸，无其它用途 */
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=image);
visibility: hidden;
}
#preview
{
/* 该对象用户在FF下显示预览图片 */
width: 740px;
height: 200px;
}
</style>
</head>
<script type="text/javascript" language="javascript">
function onUploadImgChange(sender, p, pf, psf,width,height) {
if (!sender.value.match(/.jpg|.gif|.png|.bmp/i)) //忽略大小写
{
alert('图片格式无效！');
return false;
}
var objPreview = document.getElementById(p); //图片1
var objPreviewFake = document.getElementById(pf); //图片2
var objPreviewSizeFake = document.getElementById(psf); //外套1
if (sender.files && sender.files[0])
{
objPreview.style.display = 'block';
objPreview.style.width = 'auto';
objPreview.style.height = 'auto';
objPreview.src = window.URL.createObjectURL(sender.files[0]);
}
else if (objPreviewFake.filters)
{
// IE7,IE8 在设置本地图片地址为 img.src 时出现莫名其妙的后果
//（相同环境有时能显示，有时不显示），因此只能用滤镜来解决
// IE7, IE8因安全性问题已无法直接通过 input[file].value 获取完整的文件路径
sender.select();
var imgSrc = document.selection.createRange().text;
objPreviewFake.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = imgSrc;
objPreviewSizeFake.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = imgSrc;
autoSizePreview(objPreviewFake, width, height);
objPreview.style.display = 'none';
}
}
function autoSizePreview(objPre, originalWidth, originalHeight) {
objPre.style.width = originalWidth + 'px';
objPre.style.height = originalHeight + 'px';
objPre.style.marginTop = 0 + 'px';
objPre.style.marginLeft = 0 + 'px';
}
</script>
<body>
<div id="preview_wrapper">
<div id="preview_fake">
<img id="preview" src="" alt="" onload="autoSizePreview(this,740,200)" />
<img id="preview_size_fake" src="" alt="" />
</div>
</div>
<br />
<input id="upload_img" name="upload_img" type="file" onchange="onUploadImgChange(this,'preview','preview_fake','preview_size_fake',740,200)" />
</body>
</html>
