<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="FileUpload.aspx.cs" Inherits="第六章_基本控件_.FileUpload" %><!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 runat="server">
<title></title>
<script type="text/javascript" language="javascript">
//如果用户选择了图片,则显示图片的预览效果
function previewImage()
{
var x = document.getElementById("FileUpload1");
if(!x || !x.value)//如果没有选择上传文件
{
return;
}
var patn = /[.](jpg|gif|bmg)$/ ;
if(patn.test(x.value))//如果上传文件的后缀是.jpg或.jpeg或.gif
{
var y = document.getElementById("img");
if(y)
{
y.src = 'file://localhost/' + x.value;
y.style.display="block";
}
else
{
var img=document.createElement('img');
img.setAttribute('src','file://localhost/'+x.value);
img.setAttribute('width','120');
img.setAttribute('height','90');
img.setAttribute('id','img');
document.getElementById('form1').appendChild(img);
}
setTimeout("hidden()",5000); //5秒之后执行隐藏图片的javascript方法
}
else
{
alert("您选择的似乎不是图像文件。");
}
}
//隐藏照片
function hidden()
{
var y = document.getElementById("img");
if(y)
{
document.getElementById('img').style.display="none";
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:FileUpload ID="FileUpload1" runat="server" onchange="previewImage()" onmouseover="previewImage()" />
<asp:Button ID="Button1" runat="server" Text="上传" onclick="Button1_Click" />
<asp:Literal ID="Literal1" runat="server"></asp:Literal>
</div>
</form>
</body>
</html>但结果是图片没看到(还没上传时),我的目的是选定了图片后就创建img 来预览图片的,是不是浏览器版本太高还是路径问题呢,帮忙检查下,谢谢
<head runat="server">
<title></title>
<script type="text/javascript" language="javascript">
//如果用户选择了图片,则显示图片的预览效果
function previewImage()
{
var x = document.getElementById("FileUpload1");
if(!x || !x.value)//如果没有选择上传文件
{
return;
}
var patn = /[.](jpg|gif|bmg)$/ ;
if(patn.test(x.value))//如果上传文件的后缀是.jpg或.jpeg或.gif
{
var y = document.getElementById("img");
if(y)
{
y.src = 'file://localhost/' + x.value;
y.style.display="block";
}
else
{
var img=document.createElement('img');
img.setAttribute('src','file://localhost/'+x.value);
img.setAttribute('width','120');
img.setAttribute('height','90');
img.setAttribute('id','img');
document.getElementById('form1').appendChild(img);
}
setTimeout("hidden()",5000); //5秒之后执行隐藏图片的javascript方法
}
else
{
alert("您选择的似乎不是图像文件。");
}
}
//隐藏照片
function hidden()
{
var y = document.getElementById("img");
if(y)
{
document.getElementById('img').style.display="none";
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:FileUpload ID="FileUpload1" runat="server" onchange="previewImage()" onmouseover="previewImage()" />
<asp:Button ID="Button1" runat="server" Text="上传" onclick="Button1_Click" />
<asp:Literal ID="Literal1" runat="server"></asp:Literal>
</div>
</form>
</body>
</html>但结果是图片没看到(还没上传时),我的目的是选定了图片后就创建img 来预览图片的,是不是浏览器版本太高还是路径问题呢,帮忙检查下,谢谢
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Firefox3,IE6,IE7,IE8上传图片预览</title>
<style type="text/css">
#preview_wrapper{
display:inline-block;
width:300px;
height:300px;
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:300px;
height:300px;
}
</style> <script type="text/javascript">
function onUploadImgChange(sender){
if( !sender.value.match( /.jpg|.gif|.png|.bmp/i ) ){
alert('图片格式无效!');
return false;
}
var objPreview = document.getElementById( 'preview' );
var objPreviewFake = document.getElementById( 'preview_fake' );
var objPreviewSizeFake = document.getElementById( 'preview_size_fake' );
if( sender.files && sender.files[0] ){
objPreview.style.display = 'block';
objPreview.style.width = 'auto';
objPreview.style.height = 'auto';
// Firefox 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
objPreview.src = sender.files[0].getAsDataURL();
}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,
objPreviewSizeFake.offsetWidth, objPreviewSizeFake.offsetHeight );
objPreview.style.display = 'none';
}
} function onPreviewLoad(sender){
autoSizePreview( sender, sender.offsetWidth, sender.offsetHeight );
} function autoSizePreview( objPre, originalWidth, originalHeight ){
var zoomParam = clacImgZoomParam( 300, 300, originalWidth, originalHeight );
objPre.style.width = zoomParam.width + 'px';
objPre.style.height = zoomParam.height + 'px';
objPre.style.marginTop = zoomParam.top + 'px';
objPre.style.marginLeft = zoomParam.left + 'px';
} function clacImgZoomParam( maxWidth, maxHeight, width, height ){
var param = { width:width, height:height, top:0, left:0 };
if( width>maxWidth || height>maxHeight ){
rateWidth = width / maxWidth;
rateHeight = height / maxHeight;
if( rateWidth > rateHeight ){
param.width = maxWidth;
param.height = height / rateWidth;
}else{
param.width = width / rateHeight;
param.height = maxHeight;
}
}
param.left = (maxWidth - param.width) / 2;
param.top = (maxHeight - param.height) / 2;
return param;
}
</script> </head> <body>
<div id="preview_wrapper">
<div id="preview_fake">
<img id="preview" onload="onPreviewLoad(this)"/>
</div>
</div>
<br/>
<input id="upload_img" type="file" onchange="onUploadImgChange(this)"/>
<br/>
<img id="preview_size_fake"/>
</body>
</html>
直接复制粘贴就可以,代码如下:
<html>
<head>
<title>js图片上传预览</title>
<script>
function PreviewImage(imgFile)
{
var filextension=imgFile.value.substring(imgFile.value.lastIndexOf("."),imgFile.value.length);
filextension=filextension.toLowerCase();
if ((filextension!='.jpg')&&(filextension!='.gif')&&(filextension!='.jpeg')&&(filextension!='.png')&&(filextension!='.bmp'))
{
alert("对不起,系统仅支持标准格式的照片,请您调整格式后重新上传,谢谢 !");
imgFile.focus();
}
else
{
var path;
if(document.all)//IE
{
imgFile.select();
path = document.selection.createRange().text;
document.getElementById("imgPreview").innerHTML="";
document.getElementById("imgPreview").style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled='true',sizingMethod='scale',src=\"" + path + "\")";//使用滤镜效果
}
else//FF
{
path=window.URL.createObjectURL(imgFile.files[0]);// FF 7.0以上
//path = imgFile.files[0].getAsDataURL();// FF 3.0
document.getElementById("imgPreview").innerHTML = "<img id='img1' width='120px' height='100px' src='"+path+"'/>";
//document.getElementById("img1").src = path;
}
}
}
</script>
</head>
<body>
<input type="file" onchange='PreviewImage(this)' />
<br />
<div id="imgPreview" style='width:120px; height:100px;'>
<img id="img1" src="" width="120" height="100" />
</div>
</body>
</html>
function Preview(my) {
var sender = document.getElementById("upfile");
if (!sender.value.match(/.jpg|.gif|.png|.bmp/i)) {
alert('图片格式无效!');
return false;
}
document.getElementById("pic").style.display="block";
document.getElementById("nopic").style.display="none";
document.getElementById("pic").filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = my.value;
} <div id="pic" style="filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale);
width: 160px; height: 120px; display: none;">
</div>
<img src="../images/nopic.jpg" runat="server" id="nopic" style="width: 120px; height: 140px;" />