图片预览效果---无刷新
来源：互联网 发布：蒙牛微销售软件下载 编辑：程序博客网 时间：2024/05/01 14:15
<!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><style type="text/css"> #preview_wrapper,#preview_wrapper1{ display:inline-block; width:100px; height:100px; background-color:#CCC; } #preview_fake,#preview_fake1{ /* 该对象用户在IE下显示预览图片 */ filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale); } #preview_size_fake,#Img1{ /* 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,#preview1{ /* 该对象用户在FF下显示预览图片 */ width:100px; height:100px; } </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(100, 100, 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; } //第二张图片 function onUploadImgChange1(sender) { if (!sender.value.match(/.jpg|.gif|.png|.bmp/i)) { alert('图片格式无效！'); return false; } var objPreview = document.getElementById('preview1'); var objPreviewFake = document.getElementById('preview_fake1'); var objPreviewSizeFake = document.getElementById('Img1'); 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 onPreviewLoad1(sender) { autoSizePreview(sender, sender.offsetWidth, sender.offsetHeight); } function autoSizePreview(objPre, originalWidth, originalHeight) { var zoomParam = clacImgZoomParam(100, 100, 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> <form id="form1" runat="server"> <div id="preview_wrapper" style="float:left;"> <div id="preview_fake"> <img id="preview" onload="onPreviewLoad(this)"/> </div> </div> <div id="preview_wrapper1" style="float:left;"> <div id="preview_fake1"> <img id="preview1" onload="onPreviewLoad1(this)"/> </div> </div> <br/> <!--服务器的上传空间FileUpload也一样用--><input type="file" id="id="upload_img" onchange="onUploadImgChange(this)" /> <br/> <img id="preview_size_fake"/> <br/> <input type="file" id="id="upload_img1" onchange="onUploadImgChange1(this)" /> <br/> <img id="Img1"/> </form></body></html>
