node.js - 尝试将文件加载到服务器时无法发布/上传。穆尔特

Question

我正在尝试通过 multer 中间件将文件加载到我的服务器，但服务器回复我消息:无法 POST/upload

我的后端代码是(关于multer和请求):

import multer from 'multer';

app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use((req, res, next) => {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Methods", "GET, PUT, POST, DELETE, OPTIONS");
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    next();
});
let storage = multer.diskStorage({
    destination: (req, file, cb) =>{
        cb(null, './uploads')
    },
    filename: (req, file, cb) => {
        cb(null, file.fieldname + '-' + Date.now())
    }
})

let upload = multer({ storage: storage }).single('file');

app.post('/upload', (req, res) => {
    upload(req, res, (err) =>{
        if (err) {
            return res.end("Error uploading file.");
        }
        res.end("File is uploaded");
    });
});

我的前端表单:

<form method="post" encType="multipart/form-data" action="/upload">
    <input type="file" name="file" />
     <input type="submit" value="Submit" />
</form>

我也尝试通过 Postman 发出请求并收到相同的错误。也许是因为cors政策？请帮忙。

Answer 1

您应该像这样在发布路由的定义中直接将 upload 作为中间件传递

let upload = multer({ storage: storage }).single('file');

app.post('/upload', upload, (req, res) => {
        res.end("File is uploaded");
});

upload 是一个中间件，它必须位于 /upload 请求过程中执行的中间件列表中