最近项目中用到的图片上传前预览功能，兼容IE6-9，FF
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="/1999/xhtml"><body><input type=file name="doc" id="doc" οnchange="javascript:setImagePreview();"><p><div id="localImag"><img id="preview" width=-1 height=-1 style="diplay:none" /></div></p><script>function setImagePreview() {var docObj=document.getElementById("doc");var imgObjPreview=document.getElementById("preview");if(docObj.files && docObj.files[0]){//火狐下，直接设img属性imgObjPreview.style.display = 'block';imgObjPreview.style.width = '300px';imgObjPreview.style.height = '120px';//imgObjPreview.src = docObj.files[0].getAsDataURL();//火狐7以上版本不能用上面的getAsDataURL()方式获取，需要一下方式 imgObjPreview.src = window.URL.createObjectURL(docObj.files[0]);}else{//IE下，使用滤镜docObj.select();var imgSrc = document.selection.createRange().text;var localImagId = document.getElementById("localImag");//必须设置初始大小localImagId.style.width = "300px";localImagId.style.height = "120px";//图片异常的捕捉，防止用户修改后缀来伪造图片try{localImagId.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)";localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc;}catch(e){alert("您上传的图片格式不正确，请重新选择!");return false;}imgObjPreview.style.display = 'none';document.selection.empty();}return true;}</script></body></html>
由于项目中有多个上传按钮，需要针对网上示例作一些修改，实际使用代码
View Code function setImagePreview(fileObj, previewObj, localImg) {var docObj=document.getElementById(fileObj);var imgObjPreview=document.getElementById(previewObj);if(docObj.files && docObj.files[0]){//火狐下，直接设img属性imgObjPreview.style.display = 'block';imgObjPreview.style.width = '120px';imgObjPreview.style.height = '80px';//imgObjPreview.src = docObj.files[0].getAsDataURL();//火狐7以上版本不能用上面的getAsDataURL()方式获取，需要一下方式 imgObjPreview.src = window.URL.createObjectURL(docObj.files[0]);}else{//IE下，使用滤镜docObj.select();var imgSrc = document.selection.createRange().text;var localImagId = document.getElementById(localImg);//必须设置初始大小localImagId.style.width = "120px";localImagId.style.height = "80px";//图片异常的捕捉，防止用户修改后缀来伪造图片try{localImagId.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)";localImagId.filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc;}catch(e){alert("您上传的图片格式不正确，请重新选择!");return false;}imgObjPreview.style.display = 'none';document.selection.empty();}return true;}
觉得这个人写的不错，目前兼容好几款浏览器。
原文链接 /load/archive//03/06/2381657.html
