javascript ie6/ie7/ie8和ff在线浏览图片
支持ie6~ie8, ff3.5.5以上
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<!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>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> <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)) //忽略大小写 { 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 = window.URL.createObjectURL(sender.files.item(0)); //旧的firefix3.5写法 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" /><span id="swh"></span></body></html>?