<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <body> <input type=file name="doc" id="doc" onchange="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>
原文：http://www.cnblogs.com/yudishow/p/4305571.html