这个并不是那么简单做出来的,一般情况下会加一段iframe代码,模拟ajax上传。
代码很简单,如下:
<!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/htmlcharset=utf-8" />
<title>By:DragonDean</title>
<script type="text/javascript">
//下面用于图片上传预览功能
function setImagePreview(avalue) {
var docObj=document.getElementById("doc")
var imgObjPreview=document.getElementById("preview")
if(docObj.files &&docObj.files[0])
{
//火狐下,直接设img属性
imgObjPreview.style.display = 'block'
imgObjPreview.style.width = '150px'
imgObjPreview.style.height = '180px'
//imgObjPreview.src = docObj.files[0].getAsDataURL()
//火狐7以上版本不能用上面的getAsDataURL()方式获取,需要一下方式
imgObjPreview.src = window.URL.createObjectURL(docObj.files[0])
}
else
{
//IE下,使用滤镜
docObj.select()
var imgSrc = document.selection.createRange().text
var localImagId = document.getElementById("localImag")
//必须设置初始大小
localImagId.style.width = "150px"
localImagId.style.height = "180px"
//图片异常的捕捉,防止用户修改后缀来伪造图片
try{
localImagId.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)"
localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc
}
catch(e)
{
alert("您上传的图片格式不正确,请重新选择!")
return false
}
imgObjPreview.style.display = 'none'
document.selection.empty()
}
return true
}
</script>
</head>
<body>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tbody>
<tr>
<td height="101" align="center">
<div id="localImag"><img id="preview" src="http://blog.chuangling.net/Public/images/top.jpg" width="150" height="180" style="display: blockwidth: 150pxheight: 180px"></div>
</td>
</tr>
<tr>
<td align="center" style="padding-top:10px"><input type="file" name="file"
id="doc" style="width:150px" onchange="javascript:setImagePreview()"></td>
</tr>
</tbody>
</table>
</body>
</html>