递归地

const toFormData = (f => f(f))(h => f => f(x => h(h)(f)(x)))(f => fd => pk => d => { if (d instanceof Object) { Object.keys(d).forEach(k => { const v = d[k] if (pk) k = `${pk}[${k}]` if (v instanceof Object && !(v instanceof Date) && !(v instanceof File)) { return f(fd)(k)(v) } else { fd.append(k, v) } }) } return fd })(new FormData())() let data = { name: 'John', age: 30, colors: ['red', 'green', 'blue'], children: [ { name: 'Max', age: 3 }, { name: 'Madonna', age: 10 } ] } console.log('data', data) document.getElementById("data").insertAdjacentHTML('beforeend', JSON.stringify(data)) let formData = toFormData(data) for (let key of formData.keys()) { console.log(key, formData.getAll(key).join(',')) document.getElementById("item").insertAdjacentHTML('beforeend', `<li>${key} = ${formData.getAll(key).join(',')}</li>`) } <p id="data"></p> <ul id="item"></ul>

抱歉这么晚才回答，我一直在纠结这个问题，因为Angular 2目前不支持文件上传。方法是用FormData发送一个XMLHttpRequest。我创建了一个函数来做这个。我用的是Typescript。要将其转换为Javascript只需删除数据类型声明。

/**
     * Transforms the json data into form data.
     *
     * Example:
     *
     * Input:
     * 
     * fd = new FormData();
     * dob = {
     *  name: 'phone',
     *  photos: ['myphoto.jpg', 'myotherphoto.png'],
     *  price: '615.99',
     *  color: {
     *      front: 'red',
     *      back: 'blue'
     *  },
     *  buttons: ['power', 'volup', 'voldown'],
     *  cameras: [{
     *      name: 'front',
     *      res: '5Mpx'
     *  },{
     *      name: 'back',
     *      res: '10Mpx'
     *  }]
     * };
     * Say we want to replace 'myotherphoto.png'. We'll have this 'fob'.
     * fob = {
     *  photos: [null, <File object>]
     * };
     * Say we want to wrap the object (Rails way):
     * p = 'product';
     *
     * Output:
     *
     * 'fd' object updated. Now it will have these key-values "<key>, <value>":
     *
     * product[name], phone
     * product[photos][], myphoto.jpg
     * product[photos][], <File object>
     * product[color][front], red
     * product[color][back], blue
     * product[buttons][], power
     * product[buttons][], volup
     * product[buttons][], voldown
     * product[cameras][][name], front
     * product[cameras][][res], 5Mpx
     * product[cameras][][name], back
     * product[cameras][][res], 10Mpx
     * 
     * @param {FormData}  fd  FormData object where items will be appended to.
     * @param {Object}    dob Data object where items will be read from.
     * @param {Object =   null} fob File object where items will override dob's.
     * @param {string =   ''} p Prefix. Useful for wrapping objects and necessary for internal use (as this is a recursive method).
     */
    append(fd: FormData, dob: Object, fob: Object = null, p: string = ''){
        let apnd = this.append;

        function isObj(dob, fob, p){
            if(typeof dob == "object"){
                if(!!dob && dob.constructor === Array){
                    p += '[]';
                    for(let i = 0; i < dob.length; i++){
                        let aux_fob = !!fob ? fob[i] : fob;
                        isObj(dob[i], aux_fob, p);
                    }
                } else {
                    apnd(fd, dob, fob, p);
                }
            } else {
                let value = !!fob ? fob : dob;
                fd.append(p, value);
            }
        }

        for(let prop in dob){
            let aux_p = p == '' ? prop : `${p}[${prop}]`;
            let aux_fob = !!fob ? fob[prop] : fob;
            isObj(dob[prop], aux_fob, aux_p);
        }
    }

也许你正在寻找这个，一个代码，接收你的javascript对象，从它创建一个FormData对象，然后POST它到你的服务器使用新的Fetch API:

    let myJsObj = {'someIndex': 'a value'};

    let datos = new FormData();
    for (let i in myJsObj){
        datos.append( i, myJsObj[i] );
    }

    fetch('your.php', {
        method: 'POST',
        body: datos
    }).then(response => response.json())
        .then(objson => {
            console.log('Success:', objson);
        })
        .catch((error) => {
            console.error('Error:', error);
        });

下面是一个非常简单的TypeScript实现，基于@Vladimir Novopashin和@developer033的回答。打印稿操场

type Serializeable =
    | string
    | number
    | boolean
    | null
    | Date
    | File
    | { [x: string | number]: Serializeable }
    | Array<Serializeable>;

function serialize(
    data: Serializeable,
    parentKey = '',
    formData: FormData = new FormData()
): FormData {
    if ( typeof data === 'string') {
        formData.append(parentKey, data);
    } else if ( typeof data === 'number') {
        formData.append(parentKey, data.toString());
    } else if ( typeof data === 'boolean') {
        formData.append(parentKey, data ? 'true' : 'false');
    } else if (data === null) {
        formData.append(parentKey, 'null');
    } else if (data instanceof Date) {
        formData.append(parentKey, data.toISOString());
    } else if (data instanceof File) {
        formData.append(parentKey, data);
    } else {
        // Arrays and objects
        Object.entries(data).forEach((entry: [string | number, Serializeable]) => {
            const [key, value] = entry;
            serialize(value, parentKey ? `${parentKey}[${key}]` : key.toString(), formData);
        });
    }

    return formData;
}

使用ES6和更函数式的编程方法@adeneo的答案可能是这样的:

function getFormData(object) {
    const formData = new FormData();
    Object.keys(object).forEach(key => formData.append(key, object[key]));
    return formData;
}

或者使用.reduce()和箭头函数:

const getFormData = object => Object.keys(object).reduce((formData, key) => {
    formData.append(key, object[key]);
    return formData;
}, new FormData());

尝试JSON。函数如下所示

var postData = JSON.stringify(item);
var formData = new FormData();
formData.append("postData",postData );