平常调用后端接口传参都是json对象，当提交表单遇到有附件需要传递时，通常是把附件上传单独做个接口，也有遇到后端让提交接口一并把附件传递到后端，这种情况需要把参数转成formData的数据，需要用到new FormData()。json对象转formData，一个一个的赋值代码会非常冗余，并且遇到复杂的数据结构，还需要一层一层的往下循环赋值。因此写了一个demo解决当前问题以供参考，写的不好的地方欢迎指正。

<template><div>测试页面<el-button type="primary" size="small" @click="changeHandle">json对象转formData</el-button></div>
</template><script>
export default {name: "test",data() {return {};},methods: {changeHandle() {let obj = {name: "yongqiang.chen",age: 30,likes: ["足球", "篮球", "乒乓球"],work: {address: "软件园C5",floor: 7,isWork: true,computer: {color: "black",num: 8,size: 1024,},},deepArray: [[{ name: "张三", age: 25, likes: ["七星彩", "大乐透", "双色球"] },{ name: "李四", age: 26, likes: ["轿车", "摩托车", "自行车"] },],[{ title: "隐形的翅膀", singer: "张韶涵" },{ title: "2002年的第一场雪", singer: "刀郎" },],],};let formDatas = new FormData();this.makeFormData(obj, formDatas);for (let [name, value] of formDatas) {console.log(`${name} = ${value}`);}},makeFormData(obj, form_data) {var data = [];if (obj instanceof File) {data.push({ key: "", value: obj });} else if (obj instanceof Array) {for (var j = 0, len = obj.length; j < len; j++) {var arr = this.makeFormData(obj[j]);for (var k = 0, l = arr.length; k < l; k++) {var key = !!form_data ? j + arr[k].key : "[" + j + "]" + arr[k].key;data.push({ key: key, value: arr[k].value });}}} else if (typeof obj == "object") {for (var j in obj) {var arr = this.makeFormData(obj[j]);for (var k = 0, l = arr.length; k < l; k++) {var key = !!form_data ? j + arr[k].key : "." + j + "" + arr[k].key;data.push({ key: key, value: arr[k].value });}}} else {data.push({ key: "", value: obj });}if (!!form_data) {// 封装for (var i = 0, len = data.length; i < len; i++) {form_data.append(data[i].key, data[i].value);}return form_data;} else {return data;}},},
};
</script><style>
</style>