project_03
/
03-4FormData对象.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <form id='form1'>

    </form>
    <script>
        //1.------------------------------
        //FormData+Ajax 发送请求
        //注意:专门用来发送post请求
        //以下是没有表单的情况下,创建一个空的表单元素对象并加入数据(键,值)
        var fd = new FormData();
        fd.append('name', '带司马');
        fd.append('age', '30'); //向fd中加入数据
        console.log(fd);
        var xhr = new XMLHttpRequest();
        xhr.open('post', 'http://www.liulongbin.top:3006/api/formdata')
            //xhr.send('查询字符串')
            //xhr.send(formdata对象)
        xhr.send(fd);
        //这种方法不用写请求头
        xhr.onreadystatechange = function() {
                if (xhr.readyState === 4 && xhr.status === 200) {
                    console.log(JSON.parse(xhr.responseText));
                }
            }
            //2.------------------------------------
            //获取表单元素
        var form = document.querySelector('#forml')
            //监听表单元素的submit事件
        form.addEventListener('submit', function(e) {
            e.preventDefault()
                //根据form表单创建FormData对象,会自动将表单数据填充到FormData对象中
                //这里传入的表单元素对象必须是一个dom对象
            var fd = new FormData(form);
            var xhr = new XMLHttpRequest();
            xhr.open('POST', 'http://www.liulongbin.top:3006/api/formdata');
            xhr.send(fd);
            xhr.onreadystatechange = function() {console.log(xhr.responseText)};
        })
    </script>
</body>

</html>