PHP文件上传预览

主页

<!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>
<style type="text/css">
#yl{ width:200px; height:300px; background-image:url(img/11.png); background-size:200px 300px;}
#file{ width:200px; height:300px; float:left; opacity:0;}
</style>
</head>

<body>

<form id="sc" action="chuli.php" method="post" enctype="multipart/form-data" target="shangchuan">

    <input type="hidden" name="tp" value="" id="tp" />

    <div id="yl">
        <input type="file" name="file" id="file" onchange="document.getElementById('sc').submit()" />
    </div>

</form>

<iframe style="display:none" name="shangchuan" id="shangchuan">
</iframe>

</body>

<script type="text/javascript">

//回调函数,调用该方法传一个文件路径，该变背景图
function showimg(url)
{
    var div = document.getElementById("yl");
    div.style.backgroundImage = "url("+url+")";

    document.getElementById("tp").value = url;
}

</script>

</html>

处理页面（chuli.php）

<?php

if($_FILES["file"]["error"])
{
    echo $_FILES["file"]["error"];
}
else
{
    if(($_FILES["file"]["type"]=="image/jpeg" || $_FILES["file"]["type"]=="image/png")&& $_FILES["file"]["size"]<1024000)
    {
        $fname = "./img/".date("YmdHis").$_FILES["file"]["name"];    

        $filename = iconv("UTF-8","gb2312",$fname);

        if(file_exists($filename))
        {
            echo "<script>alert('该文件已存在！');</script>";
        }
        else
        {
            move_uploaded_file($_FILES["file"]["tmp_name"],$filename);

            unlink($_POST["tp"]);

            echo "<script>parent.showimg('{$fname}');</script>";
        }

    }
}