建一个简单的显示界面：
<!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> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> </head> <body> <form id="sc" action="shangchuan.php" target="hidden_frame" method="post" enctype="multipart/form-data"> <div id="yl" style="margin-left:0px; 144px; height:170px; background-size:144px 170px; background-image:url(../chexiangqing/images/22.jpg)"> <input type="file" name="file" style="144px; height:170px; float:left; opacity:0;" width="146"
onchange="document.getElementById('sc').submit()"/> </div> <input type="button" value="保存"/> </form> <iframe style="display:none;" name="hidden_frame" id="hidden_frame"> </iframe> </body> <script type="text/javascript"> //回调函数 function showimg(aa) { var l = document.getElementById("yl"); l.style.backgroundImage = "url("+aa+")"; } </script> </html>
php处理上传预览页面：
<?php //上传文件限制 if ((($_FILES["file"]["type"] == "image/gif")|| ($_FILES["file"]["type"] == "image/jpeg")|| ($_FILES["file"]["type"] == "image/png"))&&
($_FILES["file"]["size"] < 10000000)) { //文件上传是否出错 if ($_FILES["file"]["error"] > 0) { echo "上传出错: " . $_FILES["file"]["error"] . "<br />"; } else { //判断文件是否已存在 $filename = "images/".$_FILES["file"]["name"]; $filename = iconv("UTF-8","gb2312",$filename); if (file_exists($filename)) { echo "<script language='javascript'>alert('文件已经存在！')</script>"; } else { //移动图片至保存路径，解决中文乱码问题 move_uploaded_file($_FILES["file"]["tmp_name"],$filename); echo "<script language='javascript'>parent.showimg('".$filename."')</script>"; } } } else { echo "上传失败"; } ?>