Javascript 使用 React.js 发送的 FormData 在转到 Express.js 后端时变为空

我正在创建一个图书图书馆管理CRUD，我正在使用REACTION v18. 我正在努力地将数据添加到我的mongdb图谱中，因为每当我通过Redux传递formData到axios.post时，我在后端控制器上总是得到空的req.body.

然而，当我通过表单数据向我的数据库添加数据时，当我使用postman 时，这不会发生.我的登录表单也使用axios.post运行良好，书单使用axios.get也运行良好，图书的CRUD是唯一不工作的.

这是我的bookCreate.js分:

const BookCreate = () => {
    const [title, setTitle] = useState('')
    const [responsibility, setResponsibility] = useState('')
    const [uniform_title, setUniform_title] = useState('')
    const [parallel_title, setParallel_title] = useState('')
    const [main_author, setMain_author] = useState('')
    const [other_author, setOther_author] = useState('')
    const [contributors, setContributors] = useState('')
    const [corp_author, setCorp_author] = useState('')
    const [placePub, setPlacePub] = useState('')
    const [publisher, setPublisher] = useState('')
    const [yearPub, setYearPub] = useState('')
    ...
    const submitHandler = (e) => {
        e.preventDefault();
        const formData = new FormData();
        formData.set('title', title);
        formData.set('responsibility', responsibility);
        formData.set('uniform_title', uniform_title);
        formData.set('parallel_title', parallel_title);
        formData.set('main_author', main_author);
        formData.set('other_author', other_author);
        formData.set('contributors', contributors);
        formData.set('corp_author', corp_author);
        formData.set('placePub', placePub);
        formData.set('publisher', publisher);
        formData.set('yearPub', yearPub);
       dispatch(newBooks(formData))
    }
    return (
    
     <Fragment>
            <MetaData title={'TUP-T Online Library - Admin'} />
            {/*<div className="row">*/}
                    <SideNavbarAdmin/>
                    <div></div>
                <div className="dashboard-content">
                    <div className="dashboard-page">
                        <div className="dashboard-header">
                            <h1>Add Book</h1>
                        </div> 
                        <div className="dashboard-body">
                            <form className="" onSubmit={submitHandler} encType='multipart/form-data'>
                                <div className="row g-3">
                                    <div className="col md-6">
                                        <div className="form-group">
                                            <label htmlFor="title_field">Title</label>
                                            <input
                                                type="text"
                                                id="title_field"
                                                className="form-control"
                                                name='title'
                                                value={title}
                                                onChange={(e) => setTitle(e.target.value)}
                                            />
                                        </div>
                                        ...
}

这是bookAction.js:

export const newBooks = (bookData) => async (dispatch) => {
    try {

        dispatch({ type: NEW_BOOK_REQUEST })

        const config = {
            headers: {
                 "Content-Type": "multipart/form-data"
                 // "Content-Type": "application/json"
            }
        }
        // for(var pair of bookData.entries()) {
        //    console.log(pair[0]+ ', '+ pair[1]); 
        // }

        const { data } = await axios.post('/api/v1/book/new', bookData, config)

        dispatch({
            type: NEW_BOOK_SUCCESS,
            payload: data
        })

    } catch (error) {
        dispatch({
            type: NEW_BOOK_FAIL,
            payload: error.response.data.message
        })
    }
}

这是bookController.js:

exports.createBook = async (req, res, next) => {
    console.log(req.body);
    }

我的app.js在后台:

const express = require("express");
const app = express();
const cookieParser = require("cookie-parser");
const errorMiddleware = require("./middlewares/errors");
app.use(express.json());
app.use(cookieParser());
app.use(errorMiddleware);
app.use(express.urlencoded({ extended: true }));
const book = require("./routes/book");
const auth = require("./routes/auth");
app.use("/api/v1", book);
app.use("/api/v1", auth);
app.use(errorMiddleware);
module.exports = app;