<!doctype html>
<html>
<head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type" />
<title>Image preview example</title>
<script type="text/javascript">
var loadImageFile = (function () {
if (window.FileReader) {
var oPreviewImg = null, oFReader = new window.FileReader(),
rFilter = /^(?:image\/bmp|image\/cis\-cod|image\/gif|image\/ief|image\/jpeg|image\/jpeg|image\/jpeg|image\/pipeg|image\/png|image\/svg\+xml|image\/tiff|image\/x\-cmu\-raster|image\/x\-cmx|image\/x\-icon|image\/x\-portable\-anymap|image\/x\-portable\-bitmap|image\/x\-portable\-graymap|image\/x\-portable\-pixmap|image\/x\-rgb|image\/x\-xbitmap|image\/x\-xpixmap|image\/x\-xwindowdump)$/i;
oFReader.onload = function (oFREvent) {
if (!oPreviewImg) {
var newPreview = document.getElementById("imagePreview");
oPreviewImg = new Image();
oPreviewImg.style.width = (newPreview.offsetWidth).toString() + "px";
oPreviewImg.style.height = (newPreview.offsetHeight).toString() + "px";
newPreview.appendChild(oPreviewImg);
}
oPreviewImg.src = oFREvent.target.result;
};
return function () {
var aFiles = document.getElementById("imageInput").files;
if (aFiles.length === 0) { return; }
if (!rFilter.test(aFiles[0].type)) { alert("You must select a valid image file!"); return; }
oFReader.readAsDataURL(aFiles[0]);
}
}
if (navigator.appName === "Microsoft Internet Explorer") {
return function () {
alert(document.getElementById("imageInput").value);
document.getElementById("imagePreview").filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = document.getElementById("imageInput").value;
}
}
})();
</script>
<style type="text/css">
#imagePreview {
width: 160px;
height: 120px;
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale);
}
</style>
</head>
<body>
<div id="imagePreview">
</div>
<form name="uploadForm">
<p>
<input id="imageInput" type="file" name="myPhoto" onchange="loadImageFile();" /><br />
<input type="submit" value="Send" /></p>
</form>
</body>
</html>
但是需要注意的是 在IE8中 由于IE8自作聪明的将真实路径隐藏起来了 用alert打印的结果是C:/fakepath/*.jpg 所以导致该方法无法使用
解决办法是：进入工具 -> Internet选项 -> 安全 -> 自定义级别 -> 找到“其他”中的“将本地文件上载至服务器时包含本地目录路径”，选中“启用”即可。