Javascript Fromdata 与jQuery 实现Ajax文件上传以及文件的删除

前端HTML代码：

<!DOCTYPE html>
<html>
<head>
    <title>ajax</title>
    <script type="text/javascript" src="js/jquery.js"></script>
    <meta charset="utf-8" />
    <style type="text/css">
    form{
        position: relative;
    }
    ul li{
        list-style: none;
    }
    .divide ul li img{
        width: 100px;
        border: 3px solid #eeeeee;
    }
    .selected{
        border: 3px solid #0099aa;
    }
    form input{
        position: absolute;
        top: 0;
        left: 0;
        padding: 20px;
        opacity: 0;
    }
    button{
        padding: 20px;
        background: #0099aa;
        border-radius: 3px;
        border: 2px solid #333333;
        color: #ffffff;
        font-size: 18px;
    }
    .loading{
        display: none;
    }
    pre{
        background: #000;
        color: #fff;
    }
    textarea{
        outline: none;
        border: none;
        width: 90%;
        height: 400px;
        background: none;
        color: #fff;
        font-size: 14px;
        line-height: 14px;
    }
    </style>
</head>
<body>

    <input type="file" id="file" multiple="multiple" />

    <div class="loading"><img src="loading.gif" /></div>
    <div class="divide">
        <ul>

        </ul>
    </div>

    <script type="text/javascript">
    $(function(){

        var tt;

        $("#file").change(function(){

                data = new FormData();
                data.append('files', $('#file')[0].files[0]);
                $.ajax({
                    type: "post",
                    url: "upload.php",
                    processData: false,
                    contentType: false,
                    data: data,
                    success: function(a, b, c){
                        $("div ul").append("<li class='del'>文件上传成功！<img src='" + a + "' /> <input type='text' value='"+a+"' /></li>");
                        tt = a;
                        $(".del").bind("click", function(){
                            $.ajax({
                                type: "post",
                                url: "del.php",
                                data: {
                                    a : tt,
                                },
                                success: function(a, b, c){
                                    alert(a);
                                }
                            });
                            $(this).hide(200);
                        });
                    }
                });

        });

    });
    </script>

</body>
</html>

执行文件上传 upload.php

<?php

    $origname = $_FILES["files"]["name"];
    $ext = strtolower(substr($origname, strrpos($origname, ".")+1));
    $tmpfile = $_FILES["files"]["tmp_name"];
    $filename = "./upload/".time().".".$ext;
    move_uploaded_file( $tmpfile, $filename);
    echo $filename;

?>

执行文件删除 del.php

<?php

if(unlink($_POST["a"])){
    echo "文件删除成功！";
}else{
    echo "文件删除失败！";
}

?>