<!doctype html> <html lang="en"> <head> <meta charset="UTF-8"> <title>图片上传本地预览</title> <style type="text/css"> #preview{width:260px;height:190px;border:1px solid #000;overflow:hidden;} #imghead {filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=image);} </style> <script type="text/javascript"> //图片上传预览 IE是用了滤镜。 function previewImage(file) { var MAXWIDTH = 260; var MAXHEIGHT = 180; var div = document.getElementById('preview'); if (file.files && file.files[0]) { div.innerHTML ='<img id=imghead>'; var img = document.getElementById('imghead'); img.onload = function(){ var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight); img.width = rect.width; img.height = rect.height; // img.style.marginLeft = rect.left+'px'; // img.style.marginTop = rect.top+'px'; } var reader = new FileReader(); reader.onload = function(evt){img.src = evt.target.result;} reader.readAsDataURL(file.files[0]); } else { //兼容IE var sFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="'; file.select(); var src = document.selection.createRange().text; div.innerHTML = '<img id=imghead>'; var img = document.getElementById('imghead'); img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = src; var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight); status =('rect:'+rect.top+','+rect.left+','+rect.width+','+rect.height); // div.innerHTML = "<div id=divhead style='"+rect.width+"px;height:"+rect.height+"px;margin-top:"+rect.top+"px;"+sFilter+src+""'></div>"; div.innerHTML = "<div id=divhead style='"+rect.width+"px;height:"+rect.height+"px;"+sFilter+src+""'></div>"; } } function clacImgZoomParam( maxWidth, maxHeight, width, height ){ var param = {top:0, left:0, width, height:height}; if ( width>maxWidth || height>maxHeight ) { rateWidth = width / maxWidth; rateHeight = height / maxHeight; if( rateWidth > rateHeight ) { param.width = maxWidth; param.height = Math.round(height / rateWidth); } else { param.width = Math.round(width / rateHeight); param.height = maxHeight; } } param.left = Math.round((maxWidth - param.width) / 2); param.top = Math.round((maxHeight - param.height) / 2); return param; } </script> </head> <body> <div id="preview"> <img id="imghead" border="0" src="head_180.jpg" width="180" height="180" /> </div> <input type="file" onchange="previewImage(this)" /> </body> </html>
