html代码
<div id="divPreview">
<img id="imgHeadPhoto" src="Images/Headphoto/noperson.jpg" style="width: 160px; height: 170px;border: solid 1px #d2e2e2;" alt="" />
</div>
<asp:FileUpload ID="fuHeadPhoto" runat="server" onchange="PreviewImage(this,'imgHeadPhoto','divPreview')" size="20" />
将网上的js本地图片预览整合了一下，希望对大家有用，如有其他浏览器不兼容且有解决办法，请给我留言，我将及时更新本文代码。
javascript代码
//js本地图片预览，兼容ie[6-9]、火狐、Chrome17+、Opera11+、Maxthon3、360浏览器
function PreviewImage(fileObj,imgPreviewId,divPreviewId){
var allowExtention=".jpg,.bmp,.gif,.png";//允许上传文件的后缀名document.getElementById("hfAllowPicSuffix").value;
var extention=fileObj.value.substring(fileObj.value.lastIndexOf(".")+1).toLowerCase();
var browserVersion= window.navigator.userAgent.toUpperCase();
if(allowExtention.indexOf(extention)>-1){
if(fileObj.files){//兼容chrome、火狐7+、360浏览器5.5+等，应该也兼容ie10，HTML5实现预览
if(window.FileReader){
var reader = new FileReader();
reader.onload = function(e){
document.getElementById(imgPreviewId).setAttribute("src",e.target.result);
}
reader.readAsDataURL(fileObj.files[0]);
}else if(browserVersion.indexOf("SAFARI")>-1){
alert("不支持Safari浏览器6.0以下版本的图片预览!");
}
}else if (browserVersion.indexOf("MSIE")>-1){//ie、360低版本预览
if(browserVersion.indexOf("MSIE 6")>-1){//ie6
document.getElementById(imgPreviewId).setAttribute("src",fileObj.value);
}else{//ie[7-9]
fileObj.select();
if(browserVersion.indexOf("MSIE 9")>-1)
fileObj.blur();//不加上document.selection.createRange().text在ie9会拒绝访问
var newPreview =document.getElementById(divPreviewId+"New");
if(newPreview==null){
newPreview =document.createElement("div");
newPreview.setAttribute("id",divPreviewId+"New");
newPreview.style.width = document.getElementById(imgPreviewId).width+"px";
newPreview.style.height = document.getElementById(imgPreviewId).height+"px";
newPreview.style.border="solid 1px #d2e2e2";
}
newPreview.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod='scale',src='" + document.selection.createRange().text + "')";
var tempDivPreview=document.getElementById(divPreviewId);
tempDivPreview.parentNode.insertBefore(newPreview,tempDivPreview);
tempDivPreview.style.display="none";
}
}else if(browserVersion.indexOf("FIREFOX")>-1){//firefox
var firefoxVersion= parseFloat(browserVersion.toLowerCase().match(/firefox\/([\d.]+)/)[1]);
if(firefoxVersion<7){//firefox7以下版本
document.getElementById(imgPreviewId).setAttribute("src",fileObj.files[0].getAsDataURL());
}else{//firefox7.0+
document.getElementById(imgPreviewId).setAttribute("src",window.URL.createObjectURL(fileObj.files[0]));
}
}else{
document.getElementById(imgPreviewId).setAttribute("src",fileObj.value);
}
}else{
alert("仅支持"+allowExtention+"为后缀名的文件!");
fileObj.value="";//清空选中文件
if(browserVersion.indexOf("MSIE")>-1){
fileObj.select();
document.selection.clear();
}
fileObj.outerHTML=fileObj.outerHTML;
}
}
整个测试代码：图片自己添加
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title></title>
</head>
<body>
<div id="divPreview">
<img id="imgHeadPhoto" src="noperson.jpg" style="width: 160px; height: 170px; border: solid 1px #d2e2e2;" alt="" />
</div>
<input type="file" onchange="PreviewImage(this,'imgHeadPhoto','divPreview')" size="20"/>
<script type="text/javascript">
//js本地图片预览，兼容ie[6-9]、火狐、Chrome17+、Opera11+、Maxthon3
function PreviewImage(fileObj,imgPreviewId,divPreviewId){
var allowExtention=".jpg,.bmp,.gif,.png";//允许上传文件的后缀名document.getElementById("hfAllowPicSuffix").value;
var extention=fileObj.value.substring(fileObj.value.lastIndexOf(".")+1).toLowerCase();
var browserVersion= window.navigator.userAgent.toUpperCase();
if(allowExtention.indexOf(extention)>-1){
if(fileObj.files){//HTML5实现预览，兼容chrome、火狐7+等
if(window.FileReader){
var reader = new FileReader();
reader.onload = function(e){
document.getElementById(imgPreviewId).setAttribute("src",e.target.result);
}
reader.readAsDataURL(fileObj.files[0]);
}else if(browserVersion.indexOf("SAFARI")>-1){
alert("不支持Safari6.0以下浏览器的图片预览!");
}
}else if (browserVersion.indexOf("MSIE")>-1){
if(browserVersion.indexOf("MSIE 6")>-1){//ie6
document.getElementById(imgPreviewId).setAttribute("src",fileObj.value);
}else{//ie[7-9]
fileObj.select();
if(browserVersion.indexOf("MSIE 9")>-1)
fileObj.blur();//不加上document.selection.createRange().text在ie9会拒绝访问
var newPreview =document.getElementById(divPreviewId+"New");
if(newPreview==null){
newPreview =document.createElement("div");
newPreview.setAttribute("id",divPreviewId+"New");
newPreview.style.width = document.getElementById(imgPreviewId).width+"px";
newPreview.style.height = document.getElementById(imgPreviewId).height+"px";
newPreview.style.border="solid 1px #d2e2e2";
}
newPreview.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod='scale',src='" + document.selection.createRange().text + "')";
var tempDivPreview=document.getElementById(divPreviewId);
tempDivPreview.parentNode.insertBefore(newPreview,tempDivPreview);
tempDivPreview.style.display="none";
}
}else if(browserVersion.indexOf("FIREFOX")>-1){//firefox
var firefoxVersion= parseFloat(browserVersion.toLowerCase().match(/firefox\/([\d.]+)/)[1]);
if(firefoxVersion<7){//firefox7以下版本
document.getElementById(imgPreviewId).setAttribute("src",fileObj.files[0].getAsDataURL());
}else{//firefox7.0+
document.getElementById(imgPreviewId).setAttribute("src",window.URL.createObjectURL(fileObj.files[0]));
}
}else{
document.getElementById(imgPreviewId).setAttribute("src",fileObj.value);
}
}else{
alert("仅支持"+allowExtention+"为后缀名的文件!");
fileObj.value="";//清空选中文件
if(browserVersion.indexOf("MSIE")>-1){
fileObj.select();
document.selection.clear();
}
fileObj.outerHTML=fileObj.outerHTML;
}
}
</script>
</body>
</html>
2013-7-2
1.更新原来newPreview.style.width =document.getElementById(imgPreviewId).style.width为document.getElementById(imgPreviewId).width+"px";
2013-7-4
1.更新兼容ie9浏览器、兼容360浏览器5.5+