Bruce个人博客

html

<form action="" id="form">
    <label>
        文件上传：<input type="file" name="file">
    </label>
    <input type="button" value="提交">
</form>

javaScript

    var form = document.querySelector("#form");
        var button = document.querySelector("[type='button']");
        button.onclick = function () {
            var file = document.querySelector("[type='file']");
            /*创建文件对象*/
            var formData = new FormData();
            formData.append("upload",file.files[0]);
            /*发送ajax发到后台*/
            var xl = new XMLHttpRequest();
            xl.open("post","./fel.php");
            xl.send(formData);
            xl.onreadystatechange = function (data) {
                if (xl.readyState ==4 && xl.status == 200){
                    console.log("完成")
                }
            }
        }

php /./fel.php/

<?php
    print_r($_FILES);
    $file = $_FILES['upload']['tmp_name'];
    move_uploaded_file($file,'./demol.png');
?>